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The effect of fiber length change on the mechanical properties of epoxy composites filled with short carbon fibers
No full textComposites reinforced with recycled carbon fibers have great potential for development as the amount
of recycled carbon fibers increases. High aspect ratio fibers are predicted to increase the impact
properties of epoxy composites more efficiently than spherical fibers according to the rule of mixtures.
Reinforced in this article by short carbon fibers epoxy (CFRE) were prepared by pouring techniques.
The mechanical properties of the composites were studied by measuring the impact strength using a
Charpy hammer. Finally, it can be shown that a change in fiber sizes, shapes, and aspect ratio
significantly affects the change in CFRE impact strength
Numerical analysis of the dynamic thread stretching process
No full textThe subject of the paper is the analysis of the dynamic thread stretching process under extreme
conditions of the excitation speed with the physical phenomena described in terms of rheological
models. The analysis was carried out using three basic models relating to viscoelastic bodies,
i.e. the Maxwell, Kelvin-Voigt and Standard 2 models. The relationships between the reaction forces of
the stretched threads and the input parameters of the process were included both in an analytical form
and in a numerical model. The theoretical analysis was related to the experimental tests carried out on
polyester threads with a linear mass of 84, 110 and 334 dtex, assuming the tensile speed ranging from
0.6 to 1.5 m / s. The experiment was carried out on a custom designed test stand.
In the conclusion of the obtained research, it can be stated that the most appropriate model
for the description of the analysed thread stretching process is the Standard model 2 and it should
be emphasized that the traditional analysis based on analytical relationships coincides with the results
of numerical analysis. This proves the correctness of the adopted numerical model with specific
boundary conditions
Development of antibacterial and ultraviolet protective clothing by the application of medicinal plants extract
No full textThe increasing health concern has enhanced the utilization of technical products in every field of life
from common household items to fabrics. Protection against UV is one of the main concerns of the
modern world due to the potential health risk when skin is exposed to UV. Various chemicals have been
utilized to enhance the UV protection of fabrics, but they are not green. The purpose of this research is
to examine the properties of UV protective fabrics developed by using extract of different plants. Ethanol
extract of dried leaves and seeds of three medicinal plants named Azadiarchta indica, Amaranthus viridis
and Ricinus communis were applied on fabric to enhance the antimicrobial and UV blocking properties
of the treated fabric as these plants are cheap and abundant in Pakistan. Azadiarchta indica and
Amaranthus viridis showed good antibacterial and UV blocking. On the other hand, the extract of
Ricinus communis showed excellent UV blocking but antibacterial effect was not good
The effects of light pollution on birds
No full textSztuczne oświetlenie jest jednym z najczęściej nadużywanych
dóbr cywilizacyjnych, które w znacznym stopniu oddziałuje na środowisko
naturalne. Ptaki są organizmami, których funkcjonowanie zarówno w ciągu
doby, jak i roku jest istotnie regulowane naturalnymi cyklami światła. Posiadają
fotoreceptory zlokalizowane nie tylko w siatkówce, ale także w różnych
częściach mózgu, co czyni je szczególnie wrażliwymi na światło. Z tego względu
zanieczyszczenie sztucznym światłem jest czynnikiem istotnie zaburzającym
prawidłowe funkcjonowanie ptaków. Badania udowadniają, że ekspozycja na
światło w nocy znacząco wpływa na sen, lęgi, kondycję, metabolizm,
odporność, stres, migracje oraz wiele innych aspektów życia ptaków. Światło
jest także jednym z czynników znacząco zwiększających śmiertelność ptaków,
a także ograniczającym zasięgi ich występowania. Wyniki te udowadniają jak
istotne jest ograniczanie emisji zanieczyszczenia sztucznym światłem, które
jest jednym z największych zagrożeń dla bioróżnorodności na świecie.Artificial lighting is one of the most abused benefits of civilization,
which significantly affects the natural environment. Birds’ daily and annual
activities are strongly regulated by sunlight. They possess a wide range of
photoreceptors located in several tissues in the brain, not only in the retina,
which makes them particularly sensitive to light. For this reason, ecological
light pollution significantly disrupts their natural rhythms. Research provides
that exposure to light at night affects sleeping behaviour, breeding, fitness,
metabolism, immunity, stress, migration, and many other aspects of birds’ life.
Light is also one of the factors significantly increasing bird mortality, as well as
limiting the ranges of their occurrence. This proves how important it is to
reduce the emission of artificial light pollution, which is one of the greatest
threats to biodiversity in the world
Investigation of some properties of pet (polyethylene terephthalate) poy yarns containing plasmonic boron nanoparticles additive
No full textIn this study, it was aimed to increase the contribution to the national economy based on boron, which
creates a competitive advantage in the development of new technological solutions and to expand the
use of boron products. It is necessary to create new generation textile fibers with new usage areas of rich
boron resources and to acquire boron products with high added value and new production areas for new
markets. Technological and scientific developments in the field of nanomaterials are often used in the
functionalization and modification of textile fibers. The usage properties and functions of synthetic
yarns can be improved by the utilization of nanomaterials and nano-systems. In this study, PET
(Polyethylene Terephthalate) POY (Partially Oriented Yarn) yarns containing different amounts of new
generation plasmonic nanocomposite particles [functionalized core-shell nanohybrid nanoparticles
(TiNPs@amine- functionalized GQDs@BNNS nanohybrid nanoparticles)] were produced via melt
spinning process. Then, the strength, elongation, yarn unevenness, degreasing, etc. properties of PET
POY yarns containing boron-based nanocomposite were investigated. With this study, it was ensured
that boron-based nanocomposite-doped polyester fibers containing a new generation of plasmonic
nanoparticles were developed and produced on an industrial scale
Research on surface geometry of woven fabrics of different structure
No full textThe geometric structure of surface of textile materials is of significant functional, operational and
aesthetic importance. Generally, the geometric structure of the surface of materials consists of three
main elements: shape, waviness and roughness [1,2]. Parameters characterizing a quality of fabrics
surface, i.e. surface topography are strongly related to the fabrics’ structure, raw material composition
and a way of finishing. The aim of presented work was to analyse the parameters characterizing the
geometric structure of the surface of cotton woven fabrics with different weaves. Totally, 12 fabric
variants were the objects of the investigations. They were woven fabrics of 6 weaves and 2 kinds of weft
yarn. Surface topography measurements were made by means of the MicroSpy® Profile profilometer by
FRT the art of metrology™ [3]. Using the Mark III software cooperating with the profilometer, the basic
parameters characterizing the geometric structure of the fabrics’ surface were determined according to
standard [4]. Results showed that the fabrics differ between each other in the aspect of the majority of
parameters characterizing the surface geometry. Statistical analysis confirmed that weave and linear
density of weft yarn significantly influence the surface properties of the investigated fabrics
Earth – Humanity – Sustainability – Future – Education
No full textIn the article author introduces the problems and challenges of current world concerning sustainability.
We have one planet and we should take care of it. Unfortunately, we are exploiting the Earth natural
resources as they were endless. We, as humanity, use all natural resources, available in one year, in half
of year. The 6th mass extinction of the animal species has begun. Four reasons for the sustainability crisis
are defined (world economic system, overproduction, consumerism and set of values). The solutions for
the sustainability crisis should not use the same thinking which we used when we created it. The
stakeholders who have the power to make a change are defined (consumers, economy, legislators).
Examples of good practices are presented (Green deal, Patagonia). Education is introduced as the
strongest tool to make a long-term and long-lasting change. Values for the future and competencies for
the engineers of the future are also defined. At the end it is concluded that your role in creating a
sustainable world is extremely important. Be courageous and search for the solutions outside of the
established practices. Search for the solutions with experts from other disciplines – think and act
transdisciplinary. Be aware of all possibilities – act holistically
Some like it dark? Impact of light pollution on plant reproductive success
No full textRośliny są uzależnione od sygnałów środowiskowych sterujących
ich rozwojem. Na przykład światło warunkuje efektywną fotosyntezę oraz rejestrowanie
informacji o porze dnia i roku. Sztuczne światło nocą (ALAN)
wyraźnie zmienia naturalne cykle światła/ciemności, co wpływa na kondycję
fizjologiczną roślin i ich relacje ekologiczne. ALAN może działać bezpośrednio,
poprzez modyfikację procesów fizjologicznych, takich jak fotosynteza czy
naprawa uszkodzeń powodowanych przez czynniki stresowe, oraz poprzez
modyfikowanie przebiegu procesów fenologicznych, takich jak kwitnienie bądź
dojrzewanie owoców. Możliwy jest także wpływ pośredni związany ze zmienną
reakcją zwierząt wchodzących z roślinami w różne powiązania ekologiczne,
zarówno o charakterze antagonistycznym, jak i mutualistycznym. Wszystkie te
procesy wpływają na sukces reprodukcyjny roślin, co ma znaczenie biologiczne
(stabilność populacji roślinnych, trwałość ekosystemów) oraz ekonomiczne
(produkcja żywności).Plants depend on environmental signals that control their
development. For example, light is essential for efficient photosynthesis and
for capturing information about the time of day and year. Artificial light at night
(ALAN) clearly changes the natural light/dark cycles, which affects the
physiological condition of plants and their ecological relationships. ALAN can
act directly by modifying physiological processes such as photosynthesis or
repairing stress–induced damage, and by modifying phenological processes,
eg. flowering or fruit ripening. An indirect influence related to the variable
reaction of animals involved in various ecological relationships, both
antagonistic and mutualistic, with plants is also possible. All these processes
affect the reproductive success of plants, which has biological (stability of plant
populations, durability of ecosystems) and economic (food production)
importance
Electrospun bioactive polymer/gelatin coatings for medical application - creation and investigation
No full textSkin protects human body from negative external influences; however, it has property to be injured. There are a lot of different types of medical dressings, nevertheless, electrospun materials for medical applications are on demand due to nonwoven materials properties, such as large surface area, specific porosity, polymers suitability. Natural polymers for wound dressings are highly investigated not only for their antimicrobial and anti-inflammatory properties, but for electrospinning feasibility as well. The aim of this research is to develop bioactive polymer/gelatin coating from animal waste and investigate its feasibility for medical dressing. Polyvinyl butyral (PVB) and polyvinylpyrrolidone (PVP) as polymers were chosen due to their adhesive properties, solubility in various solvents andmbiocompatibility. Gelatin as bioactive polymer was chosen due to its anti-inflammatory properties. Natural Symphytum officinale (SO) extract in compositions was used. Electrospun polymeric nano/microfibers were coated with gelatin compositions. Nano/microfibers diameters and gelatin compositions droplets sizes were evaluated. It was determined that composition modification with SO has influence on used polymers nano/microfibers diameter. Plant extract addition to polymer solution induces thinner nano/microfibers. Consequently, it was ascertained that gelatin and SO composition forms high quality droplets both on PVB/SO and PVP/SO nanofibers surface