Search results

This study aims to evaluate and assess the elastoplastic properties of Ti-6Al-4V alloy manufactured by Arcam Q20 Plus electron beam melting (EBM) machine by a tensile test campaign and micro computerized tomography (microCT) imaging.

ASTM E8 tensile test specimens are designed and manufactured by EBM at an Arcam Q20 Plus machine. Surface quality is improved by machining to discard the effect of surface roughness. After surface machining, hot isostatic pressing (HIP) post-treatment is applied to half of the specimens to remove unsolicited internal defects. ASTM E8 tensile test campaign is carried out simultaneously with digital image correlation to acquire strain data for each sample. Finally, build direction and HIP post-treatment dependencies of elastoplastic properties are analyzed by F-test and t-test statistical analyses methods.

Modulus of elasticity presents isotropic behavior for each build direction according to F-test and t-test analysis. Yield and ultimate strengths vary according to build direction and post-treatment. Stiffness and strength properties are superior to conventional Ti-6Al-4V material; however, ductility turns out to be poor for aerospace structures compared to conventional Ti-6Al-4V alloy. In addition, micro CT images show that support structure leads to dense internal defects and pores at applied surfaces. However, HIP post-treatment diminishes those internal defects and pores thoroughly.

As a novel scientific contribution, this study investigates the effects of three orthogonal build directions on elastoplastic properties, while many studies focus on only two-build directions. Evaluation of Poisson’s ratio is the other originality of this study. Furthermore, another finding through micro CT imaging is that temporary support structures result in intense defects closer to applied surfaces; hence high-stress regions of structures should be avoided to use support structures.

This study aims to investigate the effect of post-treatment on anti-corrosion performance of Al coating on the surface of Ti-6Al-4V (TC4) fastener.

The Al coatings with different layer structures were prepared on TC4 by middle-frequency and direct-current combined magnetron sputtering. The cross-sectional morphology and surface roughness of coatings were characterized by scanning electron microscope and atomic force microscope. The corrosion resistance was evaluated by electrochemical method. The monolayer coating was post-treated by Alodine chemical conversion, Ar⁺ bombardment and a combination of two methods above.

The results show that the interfaces in bilayer and trilayer coatings reduce the defects. Ar⁺ bombardment reduces the corrosion current density, and Alodine chemical conversion leads to a higher pitting corrosion potential. The combined post-treatment has the highest polarization resistance.

The corrosion resistance of the Al coating is enhanced as the layer quantity increases. The combination of two post-treatments, Ar⁺ bombardment and Alodine chemical conversion, could achieve an overall improvement in corrosion resistance of Al coating.

Credit is an essential element in the production process in agriculture. There are two sources from which farm households can access credit: institutional sources and non-institutional or informal sources of credit. The informal sources of credit, such as moneylenders, charge exorbitant rates of interest, which further puts a financial burden on the farmers. Hence, to increase the flow of credit from institutional sources, a policy known as the interest subvention scheme (ISS) was introduced in the year 2006. This paper aims to find the effect of the ISS on the behaviour of farm households.

The author has used difference-in-difference analysis for estimation. In the analysis, the author has taken Madhya Pradesh as the treatment state and Andhra Pradesh as the controlled state. The author has used the Village Dynamics in South Asia (VDSA) dataset of ICRISAT for analysis. The author has used data from 2009 to 2014 for the two states.

The author has found that the difference between the average interest rate of Andhra Pradesh and Madhya Pradesh is significant for both pre-treatment and post-treatment periods and this gap has increased after the intervention period. The results suggest that the share of informal sector borrowings has reduced in the treatment group (Madhya Pradesh) as compared to the control group (Andhra Pradesh) in the post-treatment period.

This paper is particularly important because of the dearth of literature on the impact of this scheme in India and may shed light on the much-needed policy implications of this particular policy.

The purpose of this research is to propose a flexible sensor with a weft-knitted float stitch structure and to explore knitting techniques that allow conductive yarns to be skin-tight and less exposed, reducing production processes and increasing productivity. Study its electrical conductivity in different yarn materials, knit processes and deformation ranges. The analysis is compared to provide some basis for the design of the electrodes.

The method includes five operations: (1) Analysis of the morphological appearance, tensile variation, fiber material properties and electrical conductivity of high-elastic and filament silver-plated conductive yarns. (2) Based on the knitting process of the floating yarn structure, three-dimensional modeling of the flexible sensor was carried out to explore the influence of knitting process changes on appearance characteristics. (3) The fabric samples are knitted by different silver-plated conductive yarns with different structures. Processing of experimental samples to finished size by advance shrinkage. (4) Measure the resistance of the experimental sample after the machine has been lowered and after pre-shrinking. Use the stretching machine to simulate a wearing experiment and measure the change in resistance of the sample in the 0–15% stretching range. (5) Analyze the influence factors on the conductive performance of the flexible sensor to determine whether it is suitable for textile flexible sensors.

For the float knitted flexible sensors, the floating wire projection is influenced by the elasticity of the fabric and the length of the floating wire. Compared to the plain knitted flexible sensors, it has less resistance variation and better electrical properties, making it suitable for making electrodes for textile structures. In addition, the knitting method is integrated with the intelligent monitoring clothing, which saves the process for the integration of the flexible sensor, realizes positioning and fixed-point knitting.

The sensor technology of the designed weft-knitted float structure is varied and can be freely combined and designed in a wide range. Within the good electrical conductivity, the flexible sensor can realize integrated knitting, positioning monitoring, integrating into the appearance of clothing. It can also focus on the wearing experience of wearable products so that the appearance of the monitoring clothing is close to the clothes we wear in our daily life.

In this paper, an integrated positioning knitting flexible sensor based on the weft knitting float structure is studied. The improved knitting process allows the sensing contact surface to be close to the skin and reduces the integration process. The relationship between the exposure of the silver-plated yarn on the clothing surface and the electrical conductivity is analyzed. Within a certain conductive performance, reduces the exposed area of the conductive yarn on the clothing surface and proposes a design reference for the flexible sensor appearance.

Among the various applications involving the use of microwave energy, its growing utility within the mining industry is particularly noteworthy. Conventional grinding processes are often overburdened by energy inefficiencies that are directly related to machine wear, pollution and rising project costs. In this work, we numerically investigate the effects of microwave pretreatment through a series of compression tests as a means to help mitigate these energy inefficiencies.

We investigate the effects of microwave pretreatment on various rock samples, as quantified by uniaxial compression tests. In particular, we assign sample heterogeneity based on a Gaussian statistical distribution and invoke a damage model for elemental tensile and compressive stresses based on the maximum tensile stress and the Mohr–Coulomb theories, respectively. We further couple the electromagnetic, thermal and solid displacement relations using finite element modeling.

(1) Increased power intensity during microwave pretreatment results in decreased axial compressive stress. (2) Leveraging statistics to induce variable compressive and tensile strength can greatly facilitate sample heterogeneity and prove necessary for damage modeling. (3) There exists a nonlinear trend to the reduction in smax with increasing power levels, implying an optimum energy output efficiency to create the maximum degradation-power cost relationship.

Previous research in this area has been largely limited to two-dimensional thermo-electric models. The onset of high-performance computing has allowed for the development of high-fidelity, three-dimensional models with coupled equations for electromagnetics, heat transfer and solid mechanics.

Eating disorders (EDs) remain a major health concern, and their incidence has further increased since the COVID-19 pandemic. Given the equally increasing demands on treatments and service provision and the high levels of relapse post-treatment, it is important that research explore novel and innovative interventions that can further support recovery for individuals with EDs. There is growing evidence that arts interventions are beneficial for recovery from EDs. This study aims to evaluate the feasibility of conducting a stand-up comedy course to support ED recovery.

The study used a qualitative interview study design to evaluate the recovery benefits of participating in stand-up comedy workshops for a pilot group of people in recovery from EDs (n = 10).

The comedy intervention was well-attended and had high acceptability and feasibility. For most individuals, participating in the course had a positive impact, including promoting personal recovery (PR) outcomes across all five elements of the CHIME framework. Unique assets of the course included providing participants with an opportunity to distance themselves from everyday worries of living with an ED; the opportunity to cognitively reframe situations by making them the object of humour; and providing a safe space to (re-)build a positive sense of self.

This is the first study, to the best of the authors’ knowledge, that evaluates stand-up comedy workshops for ED recovery and further demonstrates the potential of arts interventions and the relevance of PR frameworks in this field.

Lengthy and complex routes to specialist care may negatively affect clinical profiles of trauma survivors accessing mental health services. The purpose of this study was to describe the characteristics and referral pathways of a cohort of clients accepted by a specialist trauma service in England; and investigate the associations between referral pathways and clients’ clinical profiles, namely, pre-treatment levels of post-traumatic stress, depression, anxiety, stress and post-traumatic growth.

Data on 117 consecutive, accepted referrals were extracted from clients’ clinical records. Information on demographics, trauma histories, clinical presentations and referral pathways was synthesised through summary statistics. Correlational analyses were conducted to test associations with pre-treatment scores.

Clients accessing the service were highly complex and mostly experienced prolonged, interpersonal trauma. Pathways to the service varied, but 50% of the sample had at least four “steps” in their referral histories and seven previous clinical contacts. The average time between trauma and specialist referral was 16.34 years. The number of referral steps positively, significatively and moderately correlated with anxiety and stress at pre-treatment.

Limitations include issues around collecting past referral information, the small sample size for clients with available pre-treatment data and the lack of post-treatment scores.

This evaluation provides an informative overview of the characteristics and referral pathways of clients accessing a specialist trauma service. It also offers preliminary insights on the relationship between clients’ routes into the service and their clinical profiles. Practice, commissioning and research implications are discussed.

This study aims to investigate outcomes of multisystemic therapy (MST) using the Youth Level of Service/Case Management Inventory (YLS/CMI) – part I.

This study, using a pre-post design, included a sample of 2,123 Norwegian youths (mean age = 14.7, SD = 1.34). The MST team supervisors assessed the YLS/CMI risk factors in addition to five behavioral treatment goals (Lives at home, Attends school/work, No violence/threats, Law-abiding and Drug-free) before and after treatment. In addition, data included responses from parent interviews six months post treatment.

Significant correlations were found between the total and dynamic YLS/CMI change scores and the additive index of behavioral treatment goals. In addition, the YLS/CMI change scores predicted the five treatment goals at the termination of treatment and at six-month follow-up.

The results indicate that the YLS/CMI is a valuable assessment tool for predicting the achievement of MST behavioral goals in adolescents with serious problem behavior.

This study provides an evaluation of the YLS/CMI in a Norwegian context and adds support for continued use of the YLS/CMI in MST.

This paper provides new insights about the YLS/CMI inventory as a tool for examining treatment change in MST. Results show that the YLS/CMI captures relevant risk factors in the youths’ environment.

The purpose of this study is to find out the effect of consumption tax on savings behavior especially on the people who are close to their retirement.

The authors analyze the response in spending and retirement saving using a difference-in-differences regression methodology. The authors use the year since the Public Provident Fund (PPF) enrollment date for each individual as a random assignment to identify the service tax policy's causal impact. Therefore, this variable is a continuous variable defined as an individual's age until the end of the restrictions when people can withdraw money from their retirement savings account PPF without any penalty. The treatment variable is the service tax shock (increase in service tax) that happened effective 1st April 2015.

The authors find a significant effect of a change in the service tax rate on individuals' spending and PPF saving behavior. On average, individuals lower their consumption by about 14% and increase their PPF savings by 16% in response to the increase in the service tax rate. The authors find substantial heterogeneity in effect across different types of individuals. The effect is more pronounced for people closer to their retirement and needy people (defined as individuals with low traditional savings account balances).

The authors studied the effect of consumption tax on one category of savings (PPF) only. There are other savings instruments available in India. The data for those were not available to us.

This paper not only throws light on the consumption and savings behaviour of the individuals, but will also help the policy maker for framing appropriate fiscal policy.

Using a unique and proprietary data from a large bank in India, the authors analyze the effect of a tax policy change on households' consumption and retirement savings behavior. The authors find that households reduce their consumption by 14% and increase their voluntary retirement savings (Public Provident Fund aka PPF) by 16% in response to an increase in the service tax policy. Individuals close to their retirement age (55 years of age and above) and without any withdrawal restrictions from their PPF account tend to reduce their expenditures more and save more. Individuals with financial constraints and withdrawal restrictions do not reduce their expenditures significantly. To the best of the authors’ knowledge no study was done on this.

This study aims to comprehensively investigate the process-structure-property correlation of acrylonitrile butadiene styrene (ABS) parts manufactured by the overheat material extrusion (Mex) method. This study considers the relationships between the tensile and impact strength with temperature profiles, mesostructures and fracture behaviors of the ABS-printed parts.

The overheat printing condition was generated by using the highest possible printing temperature of the Mex printer used in this study together with cooling fan turned off. Temperature profiles of the polymer rasters were measured to characterize the diffusion time of the deposited rasters. Thermogravimetric analysis, differential scanning calorimetry and melt flow index were performed to study the thermal properties of the ABS feedstock. The mesostructures of the printed ABS samples were characterized by using an optical microscope, while their fracture surface was investigated using a field emission scanning electron microscope. The authors performed the tensile and impact tests following ASTM D3039 and D256-10A, respectively.

The use of the overheat Mex printing could offer better raster diffusion with reduced cooling rate and prolonged diffusion time. Consequently, the overheat printed ABS parts possessed a porosity as low as 1.35% with an increase in the weld length formed between the adjacent rasters of up to 62.5%. More importantly, the overheat printed ABS parts exhibited an increase of up to 70%, 84% and 30% in tensile strain at break, tensile toughness and impact strength, respectively, compared to their normal printed counterparts.

This study provides a facile but effective approach to fabricate highly dense and strong polymeric parts printed by Mex method for end-use applications.