Durability Values Research Articles

Pilot scale evaluation of fuel pellets production from garden waste biomass

Pelletization of garden waste, without additional binder, was investigated to produce high quality fuel pellets for energy utilization. The influence of pelletization parameters viz. feedstock moisture content (5, 15, 25, and 35%), milling size (25.4 and 6.25mm) and die size (12 and 15mm) on pellet quality and pelletization process was studied. The results showed that the studied parameters had significant effect on pellet quality. A reduction in average durability value (95.0% to 92.5%) was observed when moisture content of garden waste increased from 5% to 15%. Appropriate regression models were also developed for each quality attribute by using multiple linear regressions. Eventually, a feedstock moisture content of 5±1%, milling size of 6.35mm and die size of 15mm were found to offer standard quality pellets with optimum throughput capacity. Scanning electron microscopy image analysis showed a closer agglomeration of biomass particles when feed materials were pelletized at low moisture content. The equilibrium moisture content due to adsorption for garden waste pellet was found to be 14.6% which was quite low as compared to other feedstocks. Furthermore, we deduced from the combustion test that garden waste pellets may be conveniently used in a residential cookstove. In a nutshell, pelletization of garden waste biomass has been demonstrated at pilot scale in this study.

A review discussing elotuzumab and its use in the second-line plus treatment of multiple myeloma.

Monoclonal antibodies (mAb) represent a new frontier to treat newly diagnosed and relapsed-refractory multiple myeloma (MM). Elotuzumab, an mAb targeted SLAM7 in the plasma cells and natural killercells surface, is the first mAb approved for the treatment of relapsed-refractory MM in combination with lenalidomide and dexamethasone. This approval was the final result of several preclinical and Phase I-II clinical studies leading to ELOQUENT-2 Phase III trial that demonstrated that elotuzumab adds a significant and durable value to standard therapy, paved the way of this new treatment strategy for MM. In this review we will describe elotuzumab mechanisms of action, clinical pharmacologyand clinical studies that have led to these developments.

Experimental Researches on the Durability Indicators and the Physiological Comfort of Fabrics using the Principal Component Analysis (PCA) Method

The work pursued the distribution of combed wool fabrics destined to manufacturing of external articles of clothing in terms of the values of durability and physiological comfort indices, using the mathematical model of Principal Component Analysis (PCA). Principal Components Analysis (PCA) applied in this study is a descriptive method of the multivariate analysis/multi-dimensional data, and aims to reduce, under control, the number of variables (columns) of the matrix data as much as possible to two or three. Therefore, based on the information about each group/assortment of fabrics, it is desired that, instead of nine inter-correlated variables, to have only two or three new variables called components. The PCA target is to extract the smallest number of components which recover the most of the total information contained in the initial data.

Comparative analysis of laparotomy closure techniques

To assess experimentally different laparotomy closure techniques. Experimental research on laboratory animals was performed. Laboratory animals underwent laparotomy followed by aponeurosis suturing by using of interrupted, continuous suture and continuous suture with an arrangement of stitches at different levels. Tensometric and histological examination of tissue specimens together with sutures was made in 7, 14, 60 days after surgery. Correlation of laparotomy closure technique with values of durability, elasticity and wound process course was obtained. Continuous suture after laparotomy promotes the formation of more mature granulation tissue and more solid scar with low elasticity compared with interrupted sutures.

Research on the Low-cycle Structural Strength of the Fuel Tank Membrane

A spherical fuel tank with internal space divided into a fuel chamber and a gas chamber by a thin metal membrane is under analysis. When excessive pressure is applied to the gas chamber, the membrane expels the gas under the strain. The goal of the research is to evaluate the working order of the membrane based on low-cycle strength criteria. Its stress-strain state calculations are done with the finite elements method using the ANSYS® programme in view of the geometrical and physical nonlinearity, and contact interaction with the walls of the fuel tank. Durability evaluation is performed based on FEM calculation results. Calculated durability values correlate accurately with the performed experiments.

Analysis for Effectiveness of Bridge Management Plan Focused on the Economic Value by Multi-agent Simulation

In recent years, it has been said that the majority of the Japanese bridge which were built in the period of high economic growth in danger.When performing a maintenance and service for such bridges, various discussions have been made as to how to optimize the management.In this analysis, for management approach of the bridges, we propose a management approach that emphasizes the economic value of the bridge. The effect of proposed method is verified using a multi-agent simulation model in comparison with the durability value based on the conventional method.

Optimization of durability of Persian hand-knotted wool carpets by using desirability functions

Lower abrasion loss and compression, as well as higher compression recovery, are desirable for obtaining maximum carpet durability. Hand-made carpet manufacturers need to satisfy consumers on these diverse durability requirements. Therefore, it is necessary to optimize the carpet durability by considering several objectives simultaneously. In this investigation, carpet durability has been optimized by considering abrasion loss, compression and compression recovery simultaneously. The desirability function approach has been used to combine multiple objectives into a single objective. Knot density, pile height, number of plies in the pile yarn and pile yarn twist have been considered as the four independent variables. The optimum desirability of carpet durability was found to be 0.8. The validation sample also showed good agreement (error < 5%) with the optimized values of carpet durability attributes.

Prediction of the durability of limestone aggregates using computational techniques

The durability of aggregates is an important factor that is used as an input parameter in desirable engineering properties along with resistance to exposure conditions. However, it is sometimes difficult to determine the durability of aggregates in the laboratory (with a magnesium sulfate test) because this test is time-consuming and expensive. In this paper, the physical and mechanical properties including water absorption and the Los Angeles coefficient are tailored to the specific evaluation of the durability of limestone aggregates. However, the predictive capabilities of artificial neural networks (ANN) and hybrid particle swarm optimization-based (PSO) ANN techniques have been evaluated and compared using the same input variables. To assess the reliability of the model, some performance indices such as the correlation coefficient (R 2), the variance account for, and the root-mean-square error were calculated and compared for the two developed models. The results revealed that even though the two developed models reliably predict the durability value (magnesium sulfate value), the proposed PSO–ANN method displays an obvious potential for the reliable assessment of the value of magnesium sulfate according to the model performance criterion.

Method to Produce Durable Pellets at Lower Energy Consumption Using High Moisture Corn Stover and a Corn Starch Binder in a Flat Die Pellet Mill

A major challenge in the production of pellets is the high cost associated with drying biomass from 30 to 10% (w.b.) moisture content. At Idaho National Laboratory, a high-moisture pelleting process was developed to reduce the drying cost. In this process the biomass pellets are produced at higher feedstock moisture contents than conventional methods, and the high moisture pellets produced are further dried in energy efficient dryers. This process helps to reduce the feedstock moisture content by about 5-10% during pelleting, which is mainly due to frictional heat developed in the die. The objective of this research was to explore how binder addition influences the pellet quality and energy consumption of the high-moisture pelleting process in a flat die pellet mill. In the present study, raw corn stover was pelleted at moistures of 33, 36, and 39% (w.b.) by addition of 0, 2, and 4% pure corn starch. The partially dried pellets produced were further dried in a laboratory oven at 70 °C for 3-4 hr to lower the pellet moisture to less than 9% (w.b.). The high moisture and dried pellets were evaluated for their physical properties, such as bulk density and durability. The results indicated that increasing the binder percentage to 4% improved pellet durability and reduced the specific energy consumption by 20-40% compared to pellets with no binder. At higher binder addition (4%), the reduction in feedstock moisture during pelleting was <4%, whereas the reduction was about 7-8% without the binder. With 4% binder and 33% (w.b.) feedstock moisture content, the bulk density and durability values observed of the dried pellets were >510 kg/m3 and >98%, respectively, and the percent fine particles generated was reduced to <3%.

Method to Produce Durable Pellets at Lower Energy Consumption Using High Moisture Corn Stover and a Corn Starch Binder in a Flat Die Pellet Mill.

A major challenge in the production of pellets is the high cost associated with drying biomass from 30 to 10% (w.b.) moisture content. At Idaho National Laboratory, a high-moisture pelleting process was developed to reduce the drying cost. In this process the biomass pellets are produced at higher feedstock moisture contents than conventional methods, and the high moisture pellets produced are further dried in energy efficient dryers. This process helps to reduce the feedstock moisture content by about 5-10% during pelleting, which is mainly due to frictional heat developed in the die. The objective of this research was to explore how binder addition influences the pellet quality and energy consumption of the high-moisture pelleting process in a flat die pellet mill. In the present study, raw corn stover was pelleted at moistures of 33, 36, and 39% (w.b.) by addition of 0, 2, and 4% pure corn starch. The partially dried pellets produced were further dried in a laboratory oven at 70 °C for 3-4 hr to lower the pellet moisture to less than 9% (w.b.). The high moisture and dried pellets were evaluated for their physical properties, such as bulk density and durability. The results indicated that increasing the binder percentage to 4% improved pellet durability and reduced the specific energy consumption by 20-40% compared to pellets with no binder. At higher binder addition (4%), the reduction in feedstock moisture during pelleting was <4%, whereas the reduction was about 7-8% without the binder. With 4% binder and 33% (w.b.) feedstock moisture content, the bulk density and durability values observed of the dried pellets were >510 kg/m3 and >98%, respectively, and the percent fine particles generated was reduced to <3%.

Bioabsorbable Bypass Grafts Biofunctionalised with RGD Have Enhanced Biophysical Properties and Endothelialisation Tested In vivo.

Small diameter arterial bypass grafts are considered as unmet clinical need since the current grafts have poor patency of 25% within 5 years. We have developed a 3D scaffold manufactured from natural and synthetic biodegradable polymers, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(𝜀-caprolactone) (PCL), respectively. Further to improve the biophysical properties as well as endothelialisation, the grafts were covalently conjugated with arginine-glycine-aspartic acid (RGD) bioactive peptides. The biophysical properties as well as endothelialisation of PHBV/PCL and PCL 2 mm diameter bypass grafts were assessed with and without biofunctionalisation with RGD peptides in vitro and in vivo. Morphology of the grafts was assessed by scanning electron microscopy, whereas physico-mechanical properties were evaluated using a physiological circulating system equipped with a state of art ultrasound vascular wall tracking system. Endothelialisation of the grafts in vitro and in vivo were assessed using a cell viability assay and rat abdominal aorta replacement model, respectively. The biofunctionalisation with RGD bioactive peptides decreased mean fiber diameter and mean pore area in PHBV/PCL grafts; however, this was not the case for PCL grafts. Both PHBV/PCL and PCL grafts with RGD peptides had lower durability compared to those without; these durability values were similar to those of internal mammary artery. Modification of PHBV/PCL and PCL grafts with RGD peptides increased endothelial cell viability in vitro by a factor of eight and enhanced the formation of an endothelial cell monolayer in vivo 1 month postimplantation. In conclusion, PHBV/PCL small-caliber graft can be a suitable 3D scaffold for the development of a tissue engineering arterial bypass graft.

Specific energy consumption and quality of wood pellets produced using high-moisture lodgepole pine grind in a flat die pellet mill

In the present study a Box–Behnken experimental design was used to understand the effect of the moisture content of lodgepole pine grind (33–39%, w.b.), die speed (40–60Hz) and preheating temperature (30–90°C) on the pellet quality and specific energy consumption. The partially dried pellets produced had high-moisture content in the range of 19–28% (w.b.), and were further dried to <9% (w.b.) in a mechanical oven set at 70°C for 3h. Dried pellets were further evaluated for pellet moisture content, unit, bulk, tapped density, and durability. Response surface models developed for the product properties have adequately described the process based on coefficient of determination values. Surface plots developed indicated higher unit, bulk, and tapped density (1050, 520, 560kg/m3) are achievable at 33–35% (w.b.) moisture content of the lodgepole pine grind, die speed of 60Hz and preheating temperature of 30–60°C. Higher moisture content of 39% (w.b) reduced unit, bulk, and tapped density to <912, 396, and 452kg/m3. Higher durability values of >95% were obtained at 33–35% (w.b.) at lower preheating temperatures of 30–50°C and higher die speed of >50Hz. At 33% (w.b.) moisture content of the lodgepole pine grind, preheating temperature of 90°C, and die speed of 60Hz, the observed specific energy consumption was <116kWh/ton. Scanning electron microscope studies indicated that lignin crosslinking is the primary reason for binding of the lodgepole pine grind at high-moisture content.

Hay pellets — The influence of particle size reduction on their physical–mechanical quality and energy demand during production

The densification of hay into pellets will be a complex undertaking, strongly affected by its raw material characteristics as well as the technology used. The physical–mechanical properties of such pellets are most important and highly dependent on grinding, conditioning and the operation of the pellet press. This study tries to evaluate the most efficient way of producing high quality hay pellets by finding the lowest specific energy input while achieving the highest bulk density and durability values of the pellets in accordance with ISO 17225-6. Therefore, the performance of three different grinding techniques was researched: cutting, impact and hammer mill with different influencing parameters (mesh sizes of 2, 4, and 6mm, with or without additional aspiration). Afterwards, the densification of the ground material in a ring die press was investigated. Eventually, a hammer mill with a 4mm mesh was found to yield hay pellets with the required bulk density and durability while having the lowest specific energy input (Espec,total 157Wh/kg).

High Performance Concrete with SCM and Recycled Aggregate

In the article the possibility of utilization of two waste materials: Recycled Concrete Aggregate (RCA) fraction 4-16 mm and Class F fly ash (from coal burning power plant) in high perfor-mance concrete (HPC) was presented. Concrete with RCA were made with varying amount of cement and Suplementary Cementing Materials (SCM). The specimens of concrete were tested to compare mechanical properties as well as some properties related to the durability of concrete. Compression strength values up to 71.40 MPa were achieved and good values of properties determinig durability of reinforced concrete structures.

Model of Accumulation of a Cycle Fatigue Damage in the Multi-parametric Random Loading

The article describes the method of estimation of the fatigue life under the multi-parameter random loading. This type of loading occurs when the investigated structure is exposed to the complex load in the form of independent random processes. The processes of changing the stress tensor components in the hazardous area are independent random processes. The proposed method is based on calculating of the microplastic deformations. To calculate microplastics, the structural material model built on the description of the diagram of deformation dependence by the Bridge Ramber-Osgood is used. To identify the model of accumulation of damaged conventional, mechanical and fatigue properties of the material are used. The article presents the fundamental equations of the method. The method of accounting of the mean stress is proposed. The adequacy of the approach is confirmed by comparing the calculation results with the experimental data. Under uniaxial harmonic and random loading calculation results using the proposed model coincide with those obtained by traditional methods. In terms of the plane stress state, the difference between the calculated and experimental values of the experimental durability does not exceed 30% which is quite satisfactory for the case of a high-cycle fatigue.

Characterization of pellets from mixing olive pomace and olive tree pruning

Olive pomace is an interesting agro-industrial byproduct that can be a potential raw material for densified biomass products. At first, 2-phase (2 PH) and 3-phase (3 PH) olive pomace pellets were analyzed in order to evaluate their quality in terms of the main parameters required by the European Standard EN 17225-6.The characterization of the pure pellets has shown important problems because of out of limits values of nitrogen, durability and copper in the two olive pomace. To improve the properties of olive pomace pellets, the possibility of manufacturing pellets by mixing olive pomace and olive tree pruning (PR) was investigated.Several blends at different weight ratios were analyzed in order to verify the effect of mixing on the pellet properties. It can be concluded that the physical properties of all mixtures are in compliance with the requirements of the standard.In particular, two best blends in terms of physical, chemical and mechanical characteristics were identified as becoming potential fuel for combustion and gasification applications: 75PR252 PH (75% pruning and 25% 2-phase pomace) and 50PR503 PH (50% pruning and 50% 3-phase pomace).

Effects of sunflower meal quality on the technical parameters of the pelleting process and pellet quality

The impact of sunflower meal quality (i.e. crude protein content and crude fibre content) on the technical parameters of the pelleting process and the physical properties of produced pellets was investigated. Five model mixtures were prepared for pelleting, with different ratios of corn, sunflower meal (SFM) and soybean meal (SBM). Three grades of sunflower meal were used in the experiments with crude protein contents of approximately 37%, 40%, and 43%. Within each of the mixtures, granulation of material and retention time in the steam conditioner were varied. In order to describe the effects of the test variables on the observed responses response surface methodology, standard score analysis and principal component analysis (PCA) were used. The increase in the protein content and the decrease in the crude fibre content of sunflower meals caused an increase in the pelleting temperature, specific energy consumption, pellet hardness, and pellet durability. In addition, an increase in retention time increased specific energy consumption of pellet press, and produced fines. In terms of pellet durability values, a longer retention time was more beneficial for SFM mixtures than for SBM mixture. The type of mixture was found to be the most influential variable for second order polynomial model calculation. Standard score analysis showed that the optimum values for energy consumption, quantity of the fines, and pellet durability indices were obtained for the mixture with 40% protein SFM, with no retention after conditioning and with the finest granulation of the components (0.933). PCA showed that the first two principal components (91.10% of the total variability) enabled a neat separation of the five mixtures.

LABORATORY STUDY OF ASPHALT STARBIT E-55 POLYMER MODIFIED APPLICATION ON ASPHALT CONCRETE WEARING COURSE (AC-WC) IN TERMS OF DURABILITY AND INDIRECT TENSILE STRENGTH

The conventional asphalt road has almost been considered fail to serve the transportation needs. It is indicated by the occurrence of premature damage which is caused by vehicle load and climate. Starbit E-55, the polymer modified bitumen, is formulated to meet the requirement of transport development. Considering those needs, it is important to investigate the feasibility level of that modified bitumen as alternate asphalt instead of the conventional one. This research began with the measurement of the properties of hard layered AC-WC Starbit E-55, then comparing the result to 60/70 penetration of Pertamina asphalt. The next step is then, to determine the converted value so as to be close to that of Pertamina (60/70 penetration). This step is conducted by applying durability and ITS tests on the mixture. Result of the tests showed that hard layered AC-WC Starbit E-55 has better characteristic at 5.7% optimum level asphalt and 6.4% of Pertamina asphalt (60/70 penetration). Starbit E-55 converted level within hard-layered ACWC is 5.6%. The performance test result on immersion with variance of 1, 3, 5, 7 and 14 days shows that durability value of Starbit E-55 AC-WC has better performance. During the process, Starbit E-55 required 15.38% higher energy consumption.

Adapting Rubbish Theory for heritage tourism

Michael Thompson's Rubbish Theory explains how the values of objects change and that to understand how we value objects we need to understand ‘rubbish’, that is, objects which hold no value. He explained that most objects lose value after they are created and eventually become rubbish. However, there are some objects that maintain their value, which he calls ‘durables’. His theory explains how some objects move from rubbish to having durable value. When this theory is adapted to illustrate the multiple values attributed to objects at heritage sites, it is possible to explain how heritage tourism can result in conflict at a destination and how durable objects can lose their value, which is not possible according to Thompson.

The influence of consumption values on fast fashion brand purchases

Fast fashion brand marketers should develop marketing strategies that effectively satisfy the values consumers seek when purchasing fast fashion brands. This study aimed to identify the consumption value factors of fast fashion brands and to reveal the value factors that influence attitudes toward purchasing fast fashion brands. Data were gathered by surveying university students in the Seoul metropolitan area using convenience sampling. Three hundred and five questionnaires were used in the statistical analysis, which consisted of exploratory factor analysis using SPSS and confirmatory factor analysis and path analysis using AMOS. The factor analysis revealed the following six value factors: Emotional value, social value, price/value for money, durability value, eco-value, and consistency value. The fit statistic for the six-factor model was quite acceptable. Two of the six value factors, emotional value and price/value for money, positively influenced attitudes toward purchasing fast fashion brands. The overall fits of the revealed model suggested that the model fit the data well. The results suggested that fast fashion marketers need to understand the value factors that motivate consumers to purchase fast fashion brands. In addition, marketers should focus their efforts on satisfying emotional value and price/value for money in order to establish their brands in the increasingly competitive fast fashion industry.