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Surface modification of dental materials
No full textGlavni izazov za inženjere današnjice, koji se bave dentalnim materijalima, je proizvesti dentalne implantate koji uspješno imitiraju karakteristike prirodnih kostiju kako bi zdravlje kostiju bilo očuvano te kako bi oralna rehabilitacija bila osigurana. Dentalni implantati su uglavnom izrađeni od titanija i njegovih legura. Parametri, poput geometrije i topografije površine, su ključni za uspješan rani klinički ishod. Budući da hrapava površina pogoduje lakšem „usidrenju“ kosti, kao i biomehaničkoj stabilnosti, vrlo je važno da dentalni implantati imaju grubu površinu. Osim površinskih svojstava, kemijski sastav također pridonosi biološkim procesima tijekom oseointegracije. Glavni cilj ovoga istraživanja je modificirati površinu titanija zaštitnom i osteokonduktivnom prevlakom pomoću metode elektroispredanja. Prevlaka je sačinjena od vlakana polivinilpirolidona kao nosača kalcijevih iona. Poznato je da je kalcij nužan za zdravlje kostiju i za dobar metabolizam, stoga je važno da je aktivno uključen u proces oseointegracije jer na taj način ubrzava i pospješuje stvaranje nove kosti koja okružuje implantat. Morfologija površine modificiranog titanija ispitana je pretražnom elektronskom mikroskopijom (SEM), a kemijska analiza je provedena energijski razlučujućom rendgenskom spektrometrijom (EDS) i infracrvenom spektroskopijom s Fourierovom transformacijom uz prigušenu totalnu refleksiju (ATR-FTIR). Korozijska svojstva nemodificiranog i modificiranog titanija ispitana su u otopini umjetne sline u stvarnim uvjetima primjene pomoću elektrokemijske impedancijske spektroskopije (EIS). Rezultati ukazuju na poboljšanu zaštitu od korozije titanija s prevlakom u usporedbi s nemodificiranim titanijem.Nowadays, the major challenge for engineers is to produce dental implant surfaces that closely mimic the characteristics of natural bone to allow patients to achieve healthy bone conditions and oral rehabilitation. Most dental implants are made of titanium and its alloys. Parameters, such as geometry and surface topography, are crucial for a successful early clinical outcome. Since a rough topography favours both bone anchorage and biomechanical stability, it is of great importance that dental implants have a rough surface. In addition to the surface properties, the chemical composition also contributes to the biological processes during osseointegration. The main aim of this study was to modify the titanium surface with a protective and at the same time osteoconductive coating by the electrospinning method. The coating consists of polyvinylpyrrolidone (PVP) fibers as a carrier of calcium ions. It is known that calcium is very important for bone health and metabolism. Therefore, it should be actively involved in the osseointegration process and accelerate and promote the formation of new bone surrounding the implant. The surface morphology of the modified titanium was carried out by scanning electron microscopy (SEM) and the chemical elemental analysis of the coating by energy dispersive X-ray spectroscopy (EDS). The corrosion properties of unmodified and modified titanium were investigated in an artificial saliva solution under real application conditions by electrochemical impedance spectroscopy (EIS). The results indicate improved corrosion protection behaviour of the coated titanium compared to unmodified titanium
Biorazgradivost stabljičnih vlakana i biopolimera za agrotekstilnu namjenu
No full textBiorazgradnja, to jest biotička razgradnja polimera je kemijska razgradnja materijala izazvana djelovanjem mikroorganizama kao što su gljivice, bakterije i alge. Postupak biorazgradnje se temelji na aktivnosti živih organizama, a sam produkt se dobije razgradnjom njihovog djelovanja. Prirodni polimeri kao što su proteini, polisaharidi i nukleinske kiseline se razgrađuju reakcijama oksidacije i hidrolize. Biorazgradivi materijal razgrađuje se u biomasu, ugljikov dioksid i plin metan. U ovom radu ispitivana je biorazgradnja stabljičnih vlakana (konoplja, juta) i biopolimera (PLA) za agrotekstilnu namjenu. Da bi se ispitalo svojstvo biorazgradnje, stabljična vlakna i biopolimer su zakopani u zemlju, u kontroliranim uvjetima (laboratorij) i nekontroliranim uvjetima (utjecaj atmosferilija) u periodu od 2, 4, 7, 9 i 11 dana. Nakon izlaganja, uzorcima vlakana su ispitana svojstva finoće, čvrstoće te prekidno istezanje. Da bi se ispitao stupanj biorazgradnje, dobivene vrijednosti rezultata uspoređeni su s rezultatima kontrolnih uzoraka. Nakon provedenog istraživanja i analiziranja podataka vidljivo je da se na svim izloženim uzorcima svojstva koja potvđuju biorazgradnju bila smanjena, odnosno da su bili podvrgnuti djelovanju mikroorganizma.Biodegradation or biotic degradation of polymers is a chemical degradation of materials caused by the action of microorganisms such as fungi, bacteria, and algae. The process of biodegradation is based on the activity of living organisms, and the product itself is obtained by their degradation. Natural polymers such as proteins, polysaccharides, and nucleic acids degrade by oxidation and hydrolysis reactions. Biodegradable material decomposes into biomass, carbon dioxide, and methane gas. In this study, the biodegradation of stem fibres (hemp, jute) and biopolymers (PLA) for agrotextile purposes was investigated. To investigate the biodegradability property, bast fibres and biopolymers were buried in the ground, under controlled conditions (laboratory) and uncontrolled conditions (atmospheric influence) for a period of 2, 4, 7, 9, and 11 days. After exposure, the fibre samples were tested for properties of fineness, strength, and breaking elongation. To test the degree of biodegradation, the obtained values of the results were compared with the results of control samples. After conducting the research and analysing the data, it is visible that all exposed samples had reduced properties that confirm biodegradation, i.e., they were subjected to the action of microorganisms
Removal of anthropogenic pollutants
No full textUklanjanje antropogenih onečišćujućih tvari iz okoliša ključno je za očuvanje bioraznolikosti, kvalitete zraka, vode i tla te zaštite zdravlja ljudi. Prisutnost tih tvari, kao rezultat ljudske djelatnosti, može uzrokovati ozbiljne ekološke i zdravstvene probleme. Uzroci prisutnosti antropogenih tvari leže u neodgovornim ljudskim aktivnostima, poput nepravilnog odlaganja otpada i upotrebe štetnih kemikalija. U okviru ovog rada prikazani su procesi obrade otpadne vode onečišćene antropogenim tvarima. Rješavanje navedenog problema nužno je za stvaranje održivijeg okoliša i dugoročnu dobrobit ljudi i planeta.The removal of anthropogenic pollutants from the environment is essential for the preservation of biodiversity, air, water and soil quality and the protection of human health. The presence of these substances as a result of human activities can lead to serious environmental and health problems. The causes of the presence of anthropogenic substances lie in irresponsible human activities such as the improper disposal of waste and the use of harmful chemicals. This paper presents the processes of wastewater treatment that are contaminated by anthropogenic substances. Solving this problem is necessary for the creation of a more sustainable environment and the long-term well-being of people and the planet
Improving the production process of the equipment for transmission and distribution of electricity
No full textU ovom radu objašnjen je pristup unaprjeđenju procesa, predstavljeni su najčešći pristupi unaprjeđenju proizvodnje i predstavljeni su digitalni alati koje se koriste za prikupljanje i vizualizaciju podataka u proizvodnji. Stečena teorijska znanja iskorištena su za unaprjeđenje proizvodnog procesa jedne Hrvatske tvrtke.
Unaprjeđenje procesa predstavljeno je u tri faze: mapiranje procesa, analiza procesa i unaprjeđenje procesa. Za svaku fazu objašnjeni su alati koji se koriste u toj fazi i kako se uvidi stečeni u toj fazi vežu za sljedeću fazu. Kod pristupa unaprjeđenju proizvodnje objašnjeno je šest najčešćih pristupa: vitka proizvodnja ili Toyotin proizvodni sustav, agilna proizvodnja, teorija ograničenja, potpuno upravljanje kvalitetom, , Six Sigma i Lean Six Sigma. Kod digitalnih alata za prikupljanje i vizualizaciju detaljnije su objašnjeni SCADA i ERP sustavi, MES i Internet stvari.In this paper, the approach to process improvement is explained, the most common approaches to production improvement are presented, as well as digital tools used to collect and visualize data in production. The acquired theoretical knowledge is used to improve the production process in one Croatian company.
Process improvement is presented in three phases: process mapping, process analysis, and process improvement. For each phase, the tools used in that phase and how to apply the insights gained in that phase to the next phase are explained. In the approach to production improvement, the six most common approaches are explained: lean production or the Toyota production system, agile production, theory of constraints, total quality management, Six Sigma and Lean Six Sigma. When it comes to digital tools for collection and visualization, SCADA and ERP systems, MES and the Internet of Things are explained in more detail
Statistical analysis of data in retail
No full textFokus rada je analiza maloprodajnih podataka online platformi kako bi se utvrdila opća kretanja i korelacije zavisne varijable, predvidjela buduća potražnja te predložila optimalna lokacija skladišta tvrtke. Korišteni su stvarni podaci poslovanja maloprodajne platforme Plac.hr, ali i komplementarne baze podataka za koronavirus (Hrvatski zavod za javno zdravstvo), demografiju stanovništva (Državni zavod za statistiku, GeoPortal Zagrebačke infrastrukture prostornih podataka i dr.) i poslovanje pravnih subjekata (Financijska agencija i Poslovna Hrvatska). Podaci su u obliku vremenskih nizova (eng. time series) od 2020. do 2023. godine, a metodologija uključuje korištenje alata Google Colab za analizu i vizualizaciju podataka u programskom jeziku Python. Cilj rada je pružiti dubinsku analizu vremenskih nizova maloprodajne tvrtke, identificirati trendove, sezonalnosti i korelacije, te primijeniti modele za poboljšanje operativne učinkovitosti e-trgovine. Poseban je osvrt dan utjecaju pandemije COVID-19 na potrošačke navike.The focus of the work is the analysis of retail data from online platforms to determine general trends and correlations of the dependent variable, predict future demand, and propose the optimal location of a company's warehouse. The main dataset relied on real-life business data of the retail platform Plac.hr, as well as complimentary databases on the coronavirus pandemic (Croatian Institute of Public Health), population demography (State Statistical Office, GeoPortal of the Zagreb Spatial Data Infrastructure, etc.), business operations of legal entities (Financial Agency and Poslovna Hrvatska). The data are in the form of time series from 2020 to 2023, and the methodology includes the use of Google Colab for data analysis and visualization in the Python programming language. The work aims to provide an in-depth analysis of time series data of a retail company, identify trends, seasonality and correlations, and apply models to improve the operational efficiency of e-commerce. A special review is given to the impact of the COVID-19 pandemic on consumer habits
Workstation for bending edges of car bonnet
No full textProizvodnja karoserije automobila danas je većinom automatizirana, gdje se proizvodne operacije izvode fizički odvojene jedna od druge na radnim stanicama. U ovom radu opisan je razvoj jedne od tih radnih stanica na kojoj se savijaju rubovi poklopca motora za novi model automobila. Savijanje izvode roboti dok je glavna funkcija radne stanice prihvat i pozicioniranje poklopca motora kako bi se dobila preciznost i ponovljivost procesa. Također, objašnjeni su pojmovi i elementi koji se često koriste u proizvodnji karoserije poput referenci koja služi za pozicioniranje obratka. Opisana je i radna stanica prethodnog modela koja se nalazi na istoj liniji sa svim njenim nedostacima među kojima se ističe njeno komplicirano održavanje. U pregledu patenata i tržišta pronađeni su uređaji koji se mogu iskoristiti za prihvat i pozicioniranje poklopca motora, poput pneumatskih i električnih stegi, linearnih cilindara te vodilica za dobivanje preciznih pokreta. Zatim su izneseni svi tehnički zahtjevi i ograničenja od strane klijenta pa se mogao definirati smjer razvoja radne stanice. Definiralo se da će se koristiti pneumatska energija za dobivanje pokreta, pa su se uređaji poput električnih stegi mogli odbaciti. S obzirom na definirani smjer razvoja radne stanice, napravljena je funkcijska dekompozicija radne stanice gdje su prikazane sve funkcije i podfunkcije koja stanica mora imati. Pomoću uređaja iz pregleda patenata i tržišta napravljena je morfološka matrica za sve funkcije iz funkcijske dekompozicije. Morfološka matrica je podijeljena u dvije tablice gdje se prva odnosi na rješenja funkcija po kojima se razlikuju koncepti, dok se u drugoj nalaze rješenja funkcija koja su već definirana od strane klijenta ili nisu ključna za ovaj rad pa će se postaviti izravno u konstrukcijsku razradu. Zatim se provela evaluacija koncepata po kriterijima iz tehničkih zahtjeva radne stanice te se odabrao koncept koji odlazi u konstrukcijsku razradu. U konstrukcijskoj razradi odabrani su prikladni uređaji za pomicanje elemenata (pneumatske stege i pneumatski cilindri) s obzirom na njihovu potrebnu silu i napravljen je proračun za kritične elemente.Nowadays, the car body production is mostly automated. Production operations are performed on workstations which are physically separated from each other. This paper describes the development of the workstation for bonnet crimping of a new car model. Crimping is performed by robots, while the main function of the workstation is to grasp and to position the bonnet. This ensures precision and repeatability of the process. Furthermore, terms and elements which are often used in bodywork production are explained, such as references used for positioning the workpiece. The workstation for the previous car model, which is located on the same line, is also described. Its biggest shortcoming is complicated maintenance. A variety of devices were found in the review of patents and the market. Those devices can be used for grasping and positioning of the bonnet, such as pneumatic and electric clamps, linear cylinders and guides for obtaining precise movements. Then, the client’s technical requirements and limitations were presented to define the direction of the workstation development. It has been defined that pneumatic energy will be used to obtain motion, so devices such as electric clamps could be discarded. Regarding the defined direction of the workstation development, a functional decomposition of the workstation was created. All functions and subfunctions that a workstation must have are shown in functional decomposition. Using the devices from patent and market review, a morphological matrix was created for all the functions from the functional decomposition. The morphological matrix has been divided into two tables. The first table refers to the solutions of the functions by which the concepts differ. The second table contains solutions of the functions that have already been defined by the client or that are not essential for this paper. Therefore, the solutions of functions in the second table are directly placed in design detailing. Then, the concepts have been evaluated according to the criteria from technical requirements of the workstation and the concept which goes into design detailing was selected. In design detailing, suitable devices for moving the elements (pneumatic clamps and pneumatic cylinders) have been selected regarding their required force. Finally, calculations for critical elements have been made
Numerička analiza hlađenja cilindrične Li-ionske baterijske ćelije
No full textThe task of the thermal management systems (TMS) in the electric vehicles (EV) equipped with the Li-ion battery modules is to prevent the thermal runaway by the effective control of cell-core temperature. This is important mostly due to safety reason because over-temperature of the Li-ion batteries can induce fire and even explosion. In this thesis, it was carried out a numerical conjugate heat transfer analysis of the battery module cooling with the laminar fluid flow. Three battery cell models were analyzed, which differ by the level of geometrical details taken into account: single solid body model, model with the cell-core represented by a single solid body and model with the detailed cell-core representation. These three battery cell models are compared for three different cooling strategies: bottom cooling, single sided cooling, double sided cooling. For simplified models of the cell, it was important to determine the correct effective thermal conductivity of the cell core in the in-plane and through-plane directions. The effective thermal conductivity of the jelly-roll (cell-core) was determined based on the numerical results obtained for detailed cell-core model. All numerical simulations were performed by the computational fluid dynamic software ANSYS/Fluent.Zadatak sustava za upravljanje toplinom u električnim vozilima opremljenim Li-ionskim baterijskim modulima je spriječavanje termalnog pobjega (\textit{thermal runaway}) učinkovitom kontrolom temperature jezgri ćelija. Ovo je uglavnom važno zbog sigurnosnih razloga jer previsoka temperatura Li-ionskih baterija može izazvati požar, pa čak i eksploziju. U ovom diplomskom radu provedena je numerička analiza spregnutog prijenosa topline kroz baterijski modul koji je hlađen laminarnim strujanjem fluida. Analizirana su tri modela baterijskih ćelija, koji se razlikuju po razini geometrijskih detalja uzetih u obzir: model jednog čvrstog tijela, model s jezgrom ćelije predstavljenom jednim čvrstim tijelom i model s detaljnim prikazom jezgre ćelije. Ova tri modela baterijskih ćelija su uspoređena za tri različite strategije hlađenja: hlađenje s donje strane preko rashladne ploče, jednostrano bočno hlađenje, obostrano bočno hlađenje. Za pojednostavljene modele ćelije važno je odrediti točnu efektivnu toplinsku vodljivost jezgre ćelije u aksijalnom (odnosno tangecijalnom) i radijalnom smjeru. Efektivna toplinska vodljivost jezgre ćelije određena je na temelju numeričkih rezultata dobivenih za detaljan model jezgre ćelije. Sve numeričke simulacije izvedene su računalnim programom ANSYS/Fluent
Presentation and analysis of technological processes of the battery production line
No full textU sklopu Diplomskog rada obrađena je tvrtka Rimac Automobili. Ova trenutno najpoznatija
hrvatska tvrtka u zadnjih desetak godina doživjela je veliki rast i popularnost. Od garaže postali
su tvrtka s proizvedenim najbrže ubrzavajućim automobilom na svijetu koji ulazi u serijsku
proizvodnju. Rimac Automobili d.o.o. postaju dio Rimac grupe te obuhvaćaju dva poduzeća:
Bugatti Rimac (nastaje pripajanjem svjetski poznate marke automobila Bugatti) i Rimac
Technology (proizvodnja i razvoj baterija, različitih električnih sustava i koncepta za
proizvođače automobilske industrije). U tijeku je izgradnja mega projekta pod imenom
Campus. Detalji o navedenom obrađeni su u daljnjem tekstu.
Rimac Technology kao poduzeće u sklopu Rimac grupe razvija visoku tehnologiju u kojoj
prednjači s proizvodnjom baterija na svjetskom tržištu. Obzirom na budućnost automobilske
industrije za temu je uzet upravo tehnološki proces izrade baterije. Uz opis samog proizvoda,
detaljno je analizirana i sastavnica svakog podsklopa koji gradi bateriju te je obrađen tehnološki
proces izrade svakog od navedenih podsklopova podijeljen prema radnim stanicama. Također,
predloženo je idejno rješenje za novi koncept izrade baterija uvođenjem tehnologija povezanih
s Industrijom 4.0. Za kraj, izrađena je simulacija novog procesa izrade s fokusom na
transportnim putevima i logističkom opskrbom proizvodne linije s komponentama potrebnim
za sklapanje baterije.As part of the Master Thesis, the main topic was the company Rimac Automobili. Currently,
the most popular Croatian company has experienced great growth in the last ten years. From a
garage, they became the company with the fastest-accelerating car in the world, which goes
into series production. Rimac Automobili d.o.o. becomes part of the Rimac Group and includes
two companies: Bugatti Rimac (created by merging the world-famous car brand Bugatti) and
Rimac Technology (production and development of batteries, various electrical systems and
concepts for automotive manufacturers). The construction of a mega project called Campus is
underway. Details about this company are discussed below.
As a company within the Rimac Group, Rimac Technology is developing high technology in
which the biggest focus is on production of battery packs for the world market. Considering the
future of the automotive industry, the technological process of making a battery packs has been
taken as a main topic of this thesis. In addition to the description of the product itself, the
component of each subassembly that builds the battery is analyzed in details, and the
technological process of making each of these subassemblies is divided by workstations. Also,
a conceptual solution was proposed for a new concept of making battery packs by introducing
technologies related to Industry 4.0. Finally, a simulation of a new production process was made
with a focus on transport routes and the logistics supply of the production line with the
components needed to assemble the battery pack
Aircraft flight simulation in system failure emergency with air traffic management interaction
No full textU ovom diplomskom radu proveden je eksperiment usmjeren na analizu opterećenja pilota u
simuliranim uvjetima otkaza motora. Za potrebe simulacije u stvarnom vremenu, s pilotom u
petlji (engl. pilot-in-the-loop), korišten je matematički model modernog borbenog zrakoplova,
čije su letne karakteristike temeljene na zrakoplovu Dassault Rafale. Postojeća simulacijska
platforma nadograđena je novim prikazima instrumenata kako bi se dodatno povećala
realističnost okruženja.
Eksperimentalni zadatak uključivao je simulirani otkaz jednog od motora, pri čemu su piloti
morali uspostaviti komunikaciju s kontrolorom leta i u skladu s uputama održavati zadane
parametre leta – visinu, brzinu i kurs. Svaki je kandidat izvršio zadatak tri puta čime je
omogućena pouzdanija usporedba izvedbe.
Nakon letačkog dijela prikupljeni su i subjektivni podaci putem NASA-TLX upitnika za
procjenu mentalnog opterećenja, kao i ocjene kvalitete komunikacije s kontrolorom i samog
simulatora. Kombinacijom podataka omogućena je objektivna i subjektivna procjena razine
opterećenja i učinkovitosti pilota.This thesis presents an experiment focused on the analysis of pilot workload under simulated
flight conditions. For the purposes of real-time simulation with a pilot-in-the-loop setup, a
mathematical model of a modern fighter aircraft was employed, with flight characteristics based
on the Dassault Rafale. The existing simulation platform was enhanced with updated cockpit
displays and instrument panels to increase the realism of the virtual environment.
The experimental task involved a simulated failure of one engine, during which pilots were
required to establish communication with an air traffic controller and, in accordance with given
instructions, maintain specific flight parameters — altitude, airspeed, and heading. Each
participant performed the task three times, enabling a more reliable comparison of individual
performance.
Following the flight phase, subjective data were collected using the NASA-TLX questionnaire
to assess mental workload, along with self-reported evaluations of communication quality with
the controller. The combination of objective and subjective data allowed for a comprehensive
assessment of both the workload level and performance efficiency of the pilots
Pharmacopoeial testing in the quality control of formulated dietary supplements containing slippery elm
No full textKora crvenog brijesta ima višestruku primjenu, a koristi se ponajviše kod upale grla, za probavne smetnje te pri iritaciji kože. Zbog nedostatka uspješnosti pri liječenju IBD konvencionalnim terapijama, kao i zbog nuspojava istih, ljudska se populacija sve češće okreće alternativnim oblicima terapije, osobito biljnim pripravcima lako dostupnim u obliku dodataka prehrani. Primjena dodataka prehrani za zdravstvene probleme sve je učestalija, a uz porast tržišta, problem predstavlja i činjenica kako dodaci prehrani ne prolaze kroz ispitivanja ekvivalentna onima koja se provode za lijekove dostupne na tržištu, kao i lakoća kojom se ti dodaci prehrani mogu nabaviti. U ovom radu provedena su ispitivanja varijabilnosti mase, raspadljivosti, gubitka sušenjem i bubrenja dozirnih jedinica dodataka prehrani na bazi crvenog brijesta namijenjenih liječenju IBD-a. Svi ispitivani uzorci bili su u obliku tvrdih kapsula. Cilj istraživanja bio je procijeniti usklađenost uzoraka s kriterijima Američke farmakopeje (USP-NF) kako bi se ocijenila njihova učinkovitost i sigurnost. Rezultati ispitivanja pokazali su da su svi uzorci, osim jednog, zadovoljili kriterije za varijabilnost mase. Dva uzorka nisu zadovoljila kriterij raspadljivosti, što upućuje na moguće smanjenje djelotvornosti. Gubitak sušenjem bio je unutar dopuštenih granica za sve uzorke, što sugerira prihvatljiv sadržaj vlage i hlapljivih tvari. Međutim, niti jedan uzorak nije zadovoljio kriterij bubrenja, što upućuje na smanjen sadržaj sluzi i smanjeni demulcentni učinak analiziranih dodataka prehrani. Dobiveni rezultati upućuju na potrebu za strožim nadzorom i kontrolom kvalitete dodataka prehrani, posebice onih koji se koriste u terapijske svrhe.The bark of the slippery elm has a wide range of applications, primarily used for sore throat relief, digestive issues, and skin irritation. Due to the limited effectiveness of conventional therapies for treating inflammatory bowel disease (IBD), as well as their associated side effects, people are increasingly turning to alternative treatment options, especially herbal remedies readily available as dietary supplements. The use of dietary supplements for health issues is on the rise, and alongside the growing market, a significant concern is that such products are not subjected to testing equivalent to that required for pharmaceuticals, and they are easily accessible without medical supervision. This study tested the mass variability, disintegration, loss on drying, and swelling of slippery elm-based dietary supplements intended for IBD treatment. All tested samples were in the form of hard capsules. This work aimed to assess the compliance of these samples with the United States Pharmacopeia (USP-NF) standards to evaluate their effectiveness and safety. The results showed that all but one sample met the USP-NF criteria for mass variability. Two samples failed to meet the disintegration criterion, indicating potentially reduced effectiveness. Loss on drying was within acceptable limits for all samples, suggesting an adequate moisture and volatile compound content. However, none of the samples met the USP-NF swelling criterion, indicating a lower mucilage content and reduced demulcent effect of the analyzed supplements. These findings highlight the need for stricter oversight and quality control of dietary supplements, especially those used for therapeutic purposes