1,089 research outputs found
Investigation of tensile and flexural behavior of green composites along with their impact response at different energies
No full textGreen composites can reduce the use of synthetic fibers in many applications. The motivation behind the fabrication of green composites is their excellent biodegradability and recyclability. However, fundamental issues related to green composites are their inferior mechanical properties and the reinforcement’s hydrophilic nature. This paper presents the hand layup technique to produce green composites containing different ratios of synthetic fiber (E-glass) and natural fiber (Jute). The mechanical properties were characterized as per ASTM standards. The impact strength was also investigated for different impact energies. In addition to this, the numerical simulations using ABAQUS were performed. The experimental results for tensile and flexural results were compared and validated with finite element analysis (FEA) results. An error of nearly 4% was observed between the numerical and experimental results. The microscopic analysis of fractured tensile specimens indicated that more pull out of jute fabric in high jute weight percentage composites was the leading cause of its lower tensile strength.</p
Rashid al-Din’s “Shuab-i Pandjghana”: Research Perspectives
No full textThe author of the present study describes Rashid al-Din’s work “Shuab-i Pandjghana” obtained from the archives of the Topkapi Palace Museum in Istanbul. The article contains a brief description of the previous study of this important work. The author presents his own version about how “Shuab-i pandjghana” came to Anatolia, how the latest version of Rashid al-Din’s work corresponds to his famous composition “Compendium of Chronicles”, and tries to determine the date when this wide genealogy was created. The author also analyzes the information on the “Shuab-i pandjghana” contained in A.P.Grigoryev’s study
Recent advances in nanocellulose-based different biomaterials: types, properties, and emerging applications
No full textThe research interest in sustainable and eco-friendly materials based on natural sources has increased dramatically due to their recyclability, biodegradability, compatibility, and nontoxic behavior. Nanocellulose contains chains of glucose residue and is an abundantly available green material. Recently, nanocellulose-based green composites are under extensive exploration and gained popularity among researchers owing to their lightweight, lost cost, low density, excellent mechanical and physical characteristics. These materials have also shown tremendous potential for applications in biomedical and numerous engineering fields. The mechanical properties of these materials play a vital role in effective utilization and their exploration for future applications. This review article comprehensively presents current developments, results, and findings in the arena of green and sustainable materials. Currently, the main problem is the large variability in their properties and qualities. Nanocellulose properties are influenced by various factors, including the fiber type, ecological conditions, manufacturing methods, and any alteration of the fiber surface. Finally, the review incorporates future challenges and opportunities in the field of nano cellulosic materials.</p
Strategic Reforms for Accelerated Agricultural Growth in Pakistan
Get PDFAgricultural growth rates in the 1960s, 1970s, 1980s and 1990s show that strong growth during the 1960s was driven by several factors, including greater certainty in the use of irrigation water (as a result of an agreement with India), the introduction of productivityenhancing fertiliser-seed packages, the introduction of tubewells and the electrification of rural areas, and policy changes that improved the profitability of farming. Growth during the 1970s dropped to 2.3 percent as a result of the uncertainty created by land reforms in 1972 and 1977, severe climatic shocks, a cotton virus that depressed production for most of the decade, and political instability. The recovery in the 1980s and early 1990s can be attributed to the introduction of new cotton varieties and improved management techniques, as well as to a gradual improvement in economic incentives. Closer inspection of the nature and sources of this growth raises concerns about its sustainability and casts doubt on the ability of the sector to grow by more than 3–4 percent a year in the future. Many of the past sources of agricultural growth in Pakistan appear to have been fully exploited. Strategy for the future must effectively address the followings. Allowing the market to Operate, policy reforms that support the ongoing structural adjustment should be given top priority. To address the crisis in irrigation management market-determined incentives must be allowed to determine resource allocation within the irrigation system. Reform in extension should include establishing closer links with research institutions and reducing the number of front-line extension workers and replacing them with fewer, bettertrained workers who are more responsive to the needs of farming systems. Full-fledged land reform is difficult to enact and can be considered only after a comprehensive study of costs and benefits. Some important measures can be implemented immediately, however. Foremost is providing security of tenure to many farmers, especially tenants-at-will, thereby improving responsiveness to incentives and creating better incentives for long-term investments.
Natural fiber reinforced composites: Sustainable materials for emerging applications
No full textIn the contemporary world, natural fibers reinforced polymer composite (NFRPC) materials are of great interest owing to their eco-friendly nature, lightweight, life-cycle superiority, biodegradability, low cost, noble mechanical properties. NFRPCs are widely applied in various engineering applications and this research field is continuously developing. However, the researchers are facing numerous challenges regarding the developments and applications of NFPRCs due to the inherent characteristics of natural fibers (NFs). These challenges include quality of the fiber, thermal stability, water absorption capacity, and incompatibility with the polymer matrices. Ecological and economic concerns are animating new research in the field of NFRPCs. Furthermore, considerable research is carried out to improve the performance of NFRPCs in recent years. This review highlights some of the important breakthroughs associated with the NFRPCs in terms of sustainability, eco-friendliness, and economic perspective. It also includes hybridization of NFs with synthetic fibers which is a highly effective way of improving the mechanical properties of NFRPCs along with some chemical treatment procedures. This review also elucidates the significance of using numerical models for NFRPCs. Finally, conclusions and recommendations are drawn to assist the researchers with future research directions
Communication Technologies for Vehicles: Third International Workshop, Nets4Cars/Nets4Trains 2011 Oberpfaffenhofen, Germany, March 23-24, 2011 Proceedings
No full textThe Communication Technologies for Vehicles workshop series provides an international forum on latest technologies and research in the field of intra- and inter-vehicle communications in which to present original research results in all areas relating to communication protocols and standards, mobility and traffic models, experimental and field operational testing, and performance analysis
Tensile strength evaluation of glass/jute fibers reinforced composites: An experimental and numerical approach
No full textPolymer-based composites have an exceptional perspective to replace traditional structural materials like steel and aluminium, owing to their low weight, high strength, and outstanding performance at elevated temperatures. However, the utilization of natural reinforcements for functional polymer composites is still in infancy. In this study, the tensile properties of natural and synthetic fiber-reinforced hybrid composites are reported. Glass-jute hybrid composites, prepared through hand layup technique, were used with different glass and jute fiber stacking sequences. The experimental results stipulate that the tensile properties of glass fiber reinforced polymer (GFRP) were merely affected at lower jute fiber concentration. The strength of composites consisting of single jute fabric lamina and four glass-fiber laminas were comparable with five-laminas GFRP composites. For validation of the experimental tensile testing results, a numerical simulation was also executed. Errors between experimental and numerical simulations were found for different stacking sequences due to non-uniformity in jute fiber diameter and the manufacturing process adopted for these hybrid composites. Fractographic analysis revealed the micro voids and adhesive failure at different joining layers of fibers as the primary cause of delamination.</p
Pakistan: Breaking out of stagflation into sustained growth
Get PDFThis paper proposes that the underlying cause of the macroeconomic problems facing Pakistan today are a series of supply shocks which have constrained output growth. It is argued that while the current debate has solely focused on government expenditures and revenues, it is critical to also address the acute energy shortages which is constraining supply. The paper goes on to present four recommendations for breaking out of the present stagflation: (i) prudent macroeconomic management, (ii) reviving the role of the government in development while restoring fiscal balance, (iii) loosening monetary policy in order to spur the private sector, and (iv) improving social safety nets.Economic Growth, Supply Shock, Pakistan
Hindianizing Heidi: Working children in Abdul Rashid Kardar's Do Phool
No full textThis article addresses Do Phool (1958), Abdul Rashid Kardar's film adaptation of Johanna Spyri's classic children's novel Heidi (1880). Kadar's film reconfigures Spyri's vision of the Romantic child within the idiom of popular Hindi cinema - with its particular performance traditions and mythological allusions - in order to project an ideological image of the newly independent State. The film therefore exemplifies what Tejaswini Ganti has called (H)Indianization. Attending closely to the work of the child actors presented in the film can reveal the ideological and allegorical use of childhood in 1950s Hindi cinema, as well as the uneven development of childhood as a universal category. © 2011 The Author
Avtomatizacija BIM: Projektne možnosti za optimizacijo E energetske učinkovitosti
No full textThe building sector accounts for a significant amount of energy consumption, exerting a substantial environmental impact. Hence, prioritizing the enhancement and optimization of building energy performance is imperative for designers. However, designing such efficient buildings is a complex process, often leading designers to overlook this aspect. Many available tools primarily target energy prediction in final design stages rather than the conceptual phases, where critical decisions are made. Consequently, streamlining the initial design stage is essential. This is where Building Information Modeling (BIM) emerges as a potent force, reshaping the Architecture, Engineering, and Construction (AEC) industry. By harnessing BIM tools for automation, designers and architects can readily create energy-efficient, optimized buildings. This research aims to delve into the diverse applications of BIM automation techniques in design optimization and energy efficiency practices. The study seeks to ascertain and evaluate the potential advantages of integrating BIM automation during the design phase to bolster energy efficiency in buildings. The investigation employed several qualitative and quantitative methodologies. The methodology is concluded into three key phases: analysis of methodologies from prior studies, selecting the base-case for the study, and examining the proposed automation workflows. The study-case is a simple building designed by the author, serving as a base to assess the different workflows. The exploration encompasses three levels of methodological automation. The first level involves manual workflow application, which, while time consuming and prone to human errors, limits the design options exploration. The second level focused on visual programming workflows but struggled due to limitations and inflexibility of tools like Dynamo for automation. It\u27s evident that sole reliance on visual programming might not suffice for comprehensive automation. Integrating textual programming scripts emerges to augment and expedite the process more effectively. The final level merges both visual and textual programming, particularly Python. This workflow focused on fully automating design options generation, exporting to gbXML, optimization, and data analysis. The use of Python demonstrates its prowess in automation and data analysis, allowing for rapid, accurate creation of numerous design options. Through these investigations, the study gauges the efficacy and best practices of BIM automation in design optimization. The outcomes of the study culminate in proposed workflows for automating design optimization during early stages. Though limitations persist due to closed-source design tools, the role of programming in the design process is increasingly pivotal, offering unencumbered access to data for informed decisions.Gradbeni sektor je odgovoren za velik delež porabe energije in ima posledično znaten vpliv na okolje, zato je ena izmed prioritet načrtovalcev tudi izboljšava in optimizacija energijske učinkovitosti stavb. Vendar pa je načrtovanje energijsko učinkovitih stavb kompleksen proces, kar pogosto pomeni, da projektanti ta vidik pri načrtovanju spregledajo. Številka razpoložljiva orodja se v glavnem osredotočajo na analizo energijske porabe v zaključnih fazah načrtovanja, ne v zgodnjih, konceptualne fazah, ko se sprejemajo ključne odločitve, ki vplivajo na energijsko učinkovitost stavbe. Posledično je bistveno poenostaviti začetne faze načrtovanja. Tu se izkaže BIM (angl. Building Information Modelling) kot močno orodje, ki preoblikuje celotno gradbeno industrijo, saj lahko s pomočjo orodij BIM za avtomatizacijo načrtovalci lažje ustvarijo energetsko učinkovite in optimizirane stavbe. Namen te naloge je raziskati raznolike uporabe različnih tehnik avtomatizacije BIM za potrebe optimizacije projektnih rešitev in energijske učinkovitosti. Naloga si prizadeva ugotoviti in oceniti potencialne prednosti integracije avtomatizacije BIM tekom faze načrtovanja z namenom povečati energijske učinkovitosti stavb. Raziskava je uporabila več kvantitativnih in kvalitativnih metodologij. Metodologija je strjena v tri ključne faze: analiza metodologij iz prejšnjih študij, izbira osnovnega primera za študijo in pregled predlaganih delovnih tokov avtomatizacije. Osnovni primer, izbran za študijo primera, je enostavna stavba, ki jo je avtor naloge zasnoval z namenom testiranja različnih delovnih tokov. Raziskava zajema tri metodološke ravni avtomatizacije. Prva raven vključuje uporabo ročnega dela, ki poleg časovne potratnosti in nagnjenosti k nastopu človeških napak omejuje možnost proučevanja različnih variant projektnih rešitev. Druga raven se osredotoča na uporabo delovnih tokov, ki vključujejo vizualno programiranje. Izkaže se, da se zgolj zanašanje na vizualno programiranje morda ne zadošča za celovito avtomatizacijo. Kot dobra rešitev za povečanje učinkovitosti in pospešitev delovnega procesa se pojavi integracija tekstovnega programiranja znotraj vizualnega programiranja. Zadnja, tretja raven vključuje kombinacijo vizualnega in tekstualnega programiranja, konkretneje uporabo programskega jezika Python. Ta delovni tok se osredotoča na v celoti avtomatizirano generiranje različnih variant projektnih rešitev, izvoz v datotečni format gbXML, optimizacijo in analizo podatkov. Programski jezik Python se izkaže za zelo zmogljivega z vidika avtomatizacije in analize podatkov, saj omogoča hitro in natančno generiranje velikega števila variantnih rešitev. Rezultati opravljene študije tvorijo predlagani delovni tok za avtomatizacijo optimizacije projektnih rešitev v zgodnjih fazah načrtovanja. Čeprav so omejitve zaradi uporabe zaprto kodnih programskih orodij še vedno prisotne, postaja vloga programiranja v procesu načrtovanja vse pomembnejša, saj omogoča neoviran dostop do informacij za potrebe sprejemanja informiranih odločitev
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