Thermo physiological comfort of single jersey knitted fabric derivatives

Rajesh Mishra,Hafsa Jamshaid,Sheraz Hussain Siddique Yosfani,Uzair Hussain,Muhammad Nadeem,Michal Petru,Martin Tichy,Miroslav Muller 한국의류학회 2021 Fashion and Textiles Vol.8 No.1

The main aim of this study is to determine the thermo-physiological comfort properties of single knit fabrics and their derivatives. As the Single Jersey knitted fabrics are the most widely used fabrics in the apparel sector, they have been selected for the analysis purpose. Derivatives of single jersey are developed and compared in order to understand the infuence of structural variations. Physical properties e.g. thickness and areal density were evaluated for all knitted fabrics with 100% cotton yarn having three diferent yarn linear densities and after diferent stages of relaxation. Various thermo-physiological properties have been studied by changing the combed cotton yarn linear density as well as the structure of single knit fabric. Air permeability, thermal insulation and relative water vapor permeability of the fabrics were observed and investigated under wet relaxed states. It is determined that fabric physical properties are afected by changing yarn linear density and by the dry or wet relaxation stages. The percentage/number of tuck stitches (NTS), location of tuck stitches (LTS) and ratio of tuck to knit stitches (RTKS) have strong infuence on physical and thermo-physiological properties of single knit fabrics, even though other knitting parameters remained the same.

Effect of Stitch Characteristics on Flammability and Thermo-Physiological Comfort Properties of Knitted Fabrics

Rajesh Mishra,Hafsa Jamshaid,Sikander Abbas Basra,Gaoming Jiang,Zhe Gao,Pibo Ma,Michal Petru,Ali Raza,Miroslav Muller 한국섬유공학회 2020 Fibers and polymers Vol.21 No.11

Investigations on influence of stitch types in single jersey knitted fabric on flammability and comfort properties arecarried out in this paper. Seven different knitted structures were developed on single jersey machine. In this study the effect ofcombinations of knit, miss and tuck stitches on comfort and flammability properties of knitted fabrics are investigated. Flammability test/properties e.g. afterglow time, char length, and weight loss % are evaluated. Several tests for thermophysiologicalcomfort i.e. air permeability, thermal resistance and absorbency are also carried out. Results obtained show thatboth comfort and flammability properties are dependent on type of stitch, pattern of stitch, location of stitch and percentage ofany stitch used in the fabrics. Moreover, fabric physical parameters also affect the flammability and comfort properties. Thefindings of this study shall work as a guide for material or textile engineers in the design and selection of fabric for apparel aswell as high performance thermal protective clothing; as a result safety and occupational health of fire fighters will beimproved.

Bio-Composites Reinforced with Natural Fibers: Comparative Analysis of Thermal, Static and Dynamic-Mechanical Properties

Rajesh Mishra,Jakub Wiener,Jiri Militky,Michal Petru,Blanka Tomkova,Jana Novotna 한국섬유공학회 2020 Fibers and polymers Vol.21 No.3

In the present study, flax, jute and glass woven fabric samples were developed as reinforcement for compositeswith bio-epoxy resin. Flax fabrics were developed with plain weave, twill weave (different areal densities) and unidirectional(UD) structure. Jute fabrics were woven with three different structures i.e. plain, matt and twill respectively. For comparisonpurpose, glass woven fabric with plain weave and 3D orthogonal weave were used in this study. Static mechanical propertieslike flexural strength and impact resistance were studied. Dynamic mechanical properties were investigated by DMA 40XTRMI equipment.. Thermal conductivity has been studied for all composite samples. It is observed that the static mechanicalproperties of glass fabrics reinforced composites are superior but the flax & jute fabric reinforced composites are moreflexible. The specific flexural strength as well as specific impact strength of the flax & jute fabric reinforced composites arecompetitive. The dynamic mechanical properties are comparable to that of glass fabric reinforced composites. They can beused in relatively lower load bearing applications as they are a sustainable source of materials for bio-composites whichreduce the environmental burden and reduce the manufacturing cost.

Computational and Theoretical Studies on the Optimization of A Ballistic Range Simulator

Rupal Mishra,강현구(H. G. Kang),G. Rajesh,이정민(J. M. Lee),김희동(H. D. Kim) 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-

Utilization of Solid Waste in the Production of Autoclaved Aerated Concrete and Their Effects on its Physio-mechanical and Microstructural Properties: Alternative Sources, Characterization, and Performance Insights

Abhilasha,Rajesh Kumar,Rajni Lakhani,Raghav Kumar Mishra,Shahnavaz Khan 한국콘크리트학회 2023 International Journal of Concrete Structures and M Vol.17 No.3

Autoclaved aerated concrete (AAC) is the lightest masonry material available in today’s building industry. It shows properties, such as high strength per unit weight, lesser density, lower shrinkage, higher thermal insulation, and fire resistance as compared to traditional concrete. Not only engineering properties of AAC make it popular in construction industry, but also its eco-friendly nature also contributes in conservation of energy. AAC produces about 67% lower carbon emission than the clay bricks. Consequently, it becomes a cost-effective product which reduces the cost of construction. This paper provides thorough insight into possible solutions for the waste utilization. It has been inferred that fine aggregates can be replaced by these wastes in the preparation of AAC. This replacement will improve its physio-mechanical properties, such as bulk-density, moisture absorption, compressive strength, along with microstructure. These properties are comprehensively presented to categorize the investigation which has been done in such fields earlier. The ongoing research work at the author’s institute, i.e., the development of lightweight concrete by using different kind of waste materials, such as marble slurry, fly ash, etc., is being presented.

A Smart Building Automation System

Rohit Chasta,Rajesh Singh,Anita Gehlot,Raj Gaurav Mishra,Sushabhan Choudhury 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.8

The building energy management systems its control and automation in buildings has significant role. These systems can play an important role in regular energy monitoring and management and therefore to save the possible energy and cost. The key point of the building automation market is focused upon better facilitation to the user in terms of comfort at reduced operation cost. Energy efficiency improvement will also contribute to environmental protection. Therefore there have been regulations and rating systems made that mandates the requirement of energy monitoring and control in a building. For example, the above mentioned building utilities and equipment control and automation plays an integral role in achieving the green building rating points from certifying authorities such as GRIHA and IGBC. The proposed system is to control the active systems such as lighting including artificial lighting (on/off & dimming control), air conditioners and safety features like fire alarm & gas alarm. In future the existing idea can be implemented for the whole building, i.e. various rooms or areas and then all of them can be integrated on a common platform for monitoring and control of different equipment.

A SMART Building Automation System

Rohit Chasta,Rajesh Singh,Anita Gehlot,Raj Gaurav Mishra,Sushabhan Choudhury 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.9

The building energy management systems its control and automation in buildings has significant role. These systems can play an important role in regular energy monitoring and management and therefore to save the possible energy and cost. The key point of the building automation market is focused upon better facilitation to the user in terms of comfort at reduced operation cost. Energy efficiency improvement will also contribute to environmental protection. Therefore there have been regulations and rating systems made that mandates the requirement of energy monitoring and control in a building. For example, the above mentioned building utilities and equipment control and automation plays an integral role in achieving the green building rating points from certifying authorities such as GRIHA and IGBC. The proposed system is to control the active systems such as lighting including artificial lighting (on/off & dimming control), air conditioners and safety features like fire alarm & gas alarm. In future the existing idea can be implemented for the whole building, i.e. various rooms or areas and then all of them can be integrated on a common platform for monitoring and control of different equipment.

Design of an ON/OFF Mist Duty Cycle in Mist Bioreactors for the Growth of Hairy Roots

Ritu Ranjan,Naseem Ahmed,Rajesh Khanna,B. N. Mishra 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.1

In this study, we designed a strategy for selecting the operating conditions of a mist reactor for the growth of hairy roots. This was accomplished by developing a mathematical model to optimize the ON/OFF mist duty cycle for the specified growth of hairy roots. The availability and rate of transport of nutrients to the roots are important parameters in the design and operation of the reactor. The thin liquid film over the root surface, which continuously builds up during the ON cycle, is a major factor that limits mass transfer. The same film also acts as a finite reservoir of nutrients in the absence of any replenishment during the OFF cycle. This reservoir gets depleted as growing roots continue to consume the nutrients. As a result of this depletion the duration of the OFF cycle must be limited such that the nutrient concentration does not go below the critical value required for the specified growth rate. The depleted reservoir is then replenished during the next ON cycle to an extent that depends on feed concentration and duration of the next ON cycle. It was shown that the use of increasing feed concentrations in the fed-batch mode of operation could maintain a specified growth rate in the reactor. Interestingly, this also resulted in the efficient operation of the reactor whereby the reactor operated at slightly above the required concentration and close to the point of minimum mass transfer resistance.

Feasibility of laparoscopic cholecystectomy for symptomatic gallstone disease with portal cavernoma: Can prior portal vein decompression be avoided?

Bappaditya Har,Siddharth Mishra,Ayyar Srinivas Mahesh,Ankur Shrimal,Rajesh Bhojwani 한국간담췌외과학회 2023 Annals of hepato-biliary-pancreatic surgery Vol.27 No.4

Backgrounds/Aims: Biliary surgery in patients with extrahepatic portal vein obstruction with portal cavernoma (PC) is technically challenging, and associated with the risk of bleeding. Therefore, prior portal vein decompression is usually recommended before definitive biliary surgery. Only a few studies have so far reported the safety of isolated laparoscopic cholecystectomy. We aimed to evaluate our experience of laparoscopic cholecystectomy in patients with PC without prior portal decompression. Methods: Prospectively maintained data for patients with PC who underwent laparoscopic cholecystectomy for symptomatic gallstone disease without portal decompression were analyzed. Clinical features, imaging, intraoperative factors, conversion rate, complications of surgery, and long-term outcomes were assessed. Results: Sixteen patients underwent cholecystectomy without portal decompression from 2012 to 2021, of which interventions 14 were laparoscopic cholecystectomies. One patient required conversion (7.1%) to open surgery. Jaundice was present in 5 patients (35.7%), and underwent endoscopic stone clearance before surgery. Median intraoperative blood loss, operative time, and hospital stay were 100 mL (20−400 mL), 105 min (60−220 min), and 2 days (1−7 days), respectively. Blood transfusion was required in two patients (14.2%). Prior endoscopic or percutaneous intervention was associated with significant blood loss and prolonged intraoperative time. Conclusions: In centers with experience, prior portal decompression can be avoided in patients with PC requiring isolated cholecystectomy to treat gallstones or their complications. Laparoscopic surgery is safe and feasible for these patients, and gives excellent outcomes in the selected group.

Application of Acoustical Method to Characterize Nonwoven Material

Tao Yang,Xiaoman Xiong,Yuanfeng Wang,Rajesh Mishra,Michal Petrů,Jiří Militký 한국섬유공학회 2021 Fibers and polymers Vol.22 No.3

Some structural parameters, such as tortuosity, viscous and thermal characteristic lengths, are difficult to obtainthrough direct measurements. Existing indirect methods, i.e. acoustical method, make it possible to estimate theseparameters. This paper presents an application of acoustical inversion methods for estimating structural parameters ofpolyester nonwoven materials. A four-microphone impedance tube was used to measure sound reflection and transmissioncoefficients. The inversion methods used in this research are least square and Bayesian approaches. The least square methodwas achieved via Nelder-Mead algorithm. The Bayesian inversion process was conducted with Metropolis-Hastingsalgorithm and maximum a posteriori. Inversed parameters from two methods as well as front and back sides of nonwovenfabric were compared. Moreover, inversed porosity and airflow resistivity were compared with measured values. The resultsshow that the least square and Bayesian methods has a good agreement. Estimated parameters from Bayesian method wereselected for further analysis. A sizable differences on thermal characteristic length were found by comparing the values fromtwo sides, while the differences are relatively small for other parameters. It is also found that the inversed porosity, tortuosityare reasonable. The results suggest that the acoustical inversion methods can be used to accurately characterize polyesterfibrous materials.