Development of 2nd Generation Proteinous Bioplastics

Current environmental and economic concerns surrounding the use of petroleum-based plastics, has led to increased study of renewable natural polymers, such as proteins. Bloodmeal (BM) is a by-product of the meat industry and large volumes is sold as a low-cost fertilizer or animal feed. It contains 90 wt% proteins giving it the potential as a renewable precursor for bioplastic production. The objective of this study was to investigate the use of BM for the production of bioplastics, focusing on the use of chemical additives to facilitate thermoplastic extrusion. Literature revealed that bioplastics formation from proteins requires denaturation and unfolding using thermal and chemical means, allowing new interactions to form between chains. Thermoplastic extrusion also requires sufficient chain mobilization, enabling flow through the barrel. The proteins physiochemical characteristics, plasticizer content and chemical additives will govern its processing behavior, structural and material properties. Bloodmeal powder was extruded and injection moulded using water, sodium sulfite, sodium dodecyl sulfate (SDS) and urea as additives. The efficiency of these chemical additives was characterized by: Processability. Temperatures between 100 and 125 C produced a successful material, above this excessive covalent cross-linking occurred which reduced chain mobilization. Sodium sulfite was essential, breaking covalent bonding which allowed chain extension. The plasticizer content also strongly influenced the processability, while water and urea were essential for improved processing. Consolidation, water absorption and solubility. It was found that SDS's influence on hydrophobic interactions in combination with sodium sulfites cleavage of covalent cross-links resulted in good consolidation, water absorption and solubility. Increasing sodium sulfite increased water absorption, indicative of cross-link reduction. However, high sodium sulfite at low water concentration resulted in a degraded material. The degraded polymer showed an increase in ordered structures, due to the formation of helical conformations of the short peptide chains. Protein conformation. It was found that BM was already highly denatured, with considerable amounts of β-structures. Successful processing with required increased chain mobilization through the reduction of inter- and intra-molecular interactions which led to less ordered structures. Mechanical Properties. Water was shown to be critical for processing, enhancing the action of sodium sulfite, SDS and urea. During conditioning, water would evaporate, allowing new intermolecular forces between chains, often resulting in a brittle material. SDS was essential for consolidation, but excessive amounts could restrict formation of new intermolecular forces during conditioning. The highly plasticized proteins resulted in ductile materials after conditioning. Lowering the water, sodium sulfite or urea concentration would result in a brittle material after conditioning. Successful processability, consolidation, water absorption, solubility, and mechanical properties were achieved using 3 pphbm sodium sulfite, 60 pphbm water, 3 pphbm SDS and 20 pphbm urea. This optimal material resulted in increased unordered structures shown by Fourier transform infra-red spectroscopy. The resulting bioplastic was ductile after conditioning and had a tensile strength of 9.6 MPa and a Young's modulus of 536 MPa, comparable to low-density polyethylene

Formula SAE Cooling System Design

The overall objective of this senior project is to develop, via testing and analysis, a guided process that will aid the Cal Poly Formula SAE team in designing their cooling system. More specifically, a set of designed tests will yield the results necessary in determining a combination of fan and radiator that will achieve appropriate cooling. A test section that has the capability of interfacing with both the wind tunnel in the Thermal Science Lab and a radiator will be used to facilitate the necessary experiments. The wind tunnel is powered by fan controlled by a variable frequency drive that can induce a range of air flow rates through the duct and radiator. Five tests will be performed, whose goals are as follows: Determine mass flow rate of the cooling water as a function of the crank shaft rotational speed. Determine heat rejected from the engine to the cooling water as a function of crank shaft rotational speed. Determine the mass flow rate of air through the core as a function of car speed. Determine static pressure drop of the air across the radiator core at varying air mass flow rates. Determine the heat rejection rate associated with a test radiator as a function of both the mass flow rate of air through the core and the mass flow rate of cooling water. These tests will develop relationships that will ultimately allow the formula team to predict the heat rejection necessary at every car speed as well as the ability of a particular radiator to reject heat at those speeds. A guided process will be presented that will aid the team in designing the cooling system to be used on the formula competition car. By performing these tests, the FSAE team can choose an appropriate radiator type and face area for the racecar’s specific cooling needs each year. This process will allow the team to minimize the radiator’s size and optimize cooling to increase performance. The following report will detail background information regarding a car’s cooling system, a description of conceptual designs, the final design process, the test procedures and finally sample results produced via testing

Pilot scale pyrolysis - determination of critical moisture content for sustainable organic waste pyrolysis

Economic feasibility of large scale organic waste pyrolysis was investigated for Inghams Enterprise (Waitoa) chicken dissolved air flotation sludge (DAF) and activated sludge (biosolids) from the Hamilton municipal waste water treatment plant. Processing data was obtained from pilot plant trials using the Lakeland Steel (Rotorua) continuous auger pyrolysis plant using feedstock at 15, 30, 45 and ~80% moisture contents. Economics were calculated based on estimated capital and operating costs of a large scale facility, revenue from selling char, savings from landfill diversion (including transportation and gate costs), energy savings by recycling syngas product and using waste heat for drying feedstock. For DAF, 15% moisture content gave yields of 21% syngas, 27% char, and 52% oil (dry weight basis). 15% moisture content gave the best processing conditions based on handling properties and degree of autogenesis. The DAF case does not give a payback period due to low scale of operations. For biosolids, 15% moisture content feedstock gave yields of 46% syngas, 31% char, and 21% oil (wet weight). Difficulties were found with plant blockages at 45% and 80% moisture contents. 15% moisture content gave the best processing conditions and the best economic performance with a payback time of 4.6 years for a facility that could process 11,000 tonnes per year

Number-related Brain Potentials Are Differentially Affected by Mapping Novel Symbols on Small versus Large Quantities in a Number Learning Task

The nature of the mapping process that imbues number symbols with their numerical meaning-known as the "symbolgrounding process"-remains poorly understood and the topic of much debate. The aim of this study was to enhance insight into how the nonsymbolic-symbolic number mapping process and its neurocognitive correlates might differ between small (1-4; subitizing range) and larger (6-9) numerical ranges. Hereto, 22 young adults performed a learning task in which novel symbols acquired numerical meaning by mapping them onto nonsymbolic magnitudes presented as dot arrays (range 1-9). Learning-dependent changes in accuracy and RT provided evidence for successful novel symbol quantity mapping in the subitizing (1-4) range only. Corroborating these behavioral results, the number processing related P2p component was only modulated by the learning/mapping of symbols representing small numbers 1-4. The symbolic N1 amplitude increased with learning independent of symbolic numerical range but dependent on the set size of the preceding dot array; it only occurred when mapping on one to four item dot arrays that allow for quick retrieval of a numeric value, on the basis of which, with learning, one could predict the upcoming symbol causing perceptual expectancy violation when observing a different symbol. These combined results suggest that exact nonsymbolic-symbolic mapping is only successful for small quantities 1-4 from which one can readily extract cardinality. Furthermore, we suggest that the P2p reflects the processing stage of first access to or retrieval of numeric codes and might in future studies be used as a neural correlate of nonsymbolic-symbolic mapping/symbol learning

Communication-Efficient Multi-Party Computation for RMS Programs

Despite much progress, general-purpose secure multi-party computation (MPC) with active security may still be prohibitively expensive in settings with large input datasets. This particularly applies to the secure evaluation of graph algorithms, where each party holds a subset of a large graph. Recently, Araki et al. (ACM CCS \u2721) showed that dedicated solutions may provide significantly better efficiency if the input graph is sparse. In particular, they provide an efficient protocol for the secure evaluation of message passing algorithms, such as the PageRank algorithm. Their protocol\u27s computation and communication complexity are both $\tilde{O}(M\cdot B)$ instead of the $O(M^2)$ complexity achieved by general-purpose MPC protocols, where $M$ denotes the number of nodes and $B$ the (average) number of incoming edges per node. On the downside, their approach achieves only a relatively weak security notion; $1$-out-of-$3$ malicious security with selective abort. In this work, we show that PageRank can instead be captured efficiently as a restricted multiplication straight-line (RMS) program, and present a new actively secure MPC protocol tailored to handle RMS programs. In particular, we show that the local knowledge of the participants can be leveraged towards the first maliciously-secure protocol with communication complexity linear in $M$, independently of the sparsity of the graph. We present two variants of our protocol. In our communication-optimized protocol, going from semi-honest to malicious security only introduces a small communication overhead, but results in quadratic computation complexity $O(M^2)$. In our balanced protocol, we still achieve a linear communication complexity $O(M)$, although with worse constants, but a significantly better computational complexity scaling with $O(M\cdot B)$. Additionally, our protocols achieve security with identifiable abort and can tolerate up to $n-1$ corruptions

Cognitive and Behavioral Resilience Among Young Gay and Bisexual Men Living with HIV

Purpose: HIV/AIDS disproportionately affects young gay, bisexual, and other men who have sex with men (Y-GBMSM). Resilience remains understudied among Y-GBMSM living with HIV, but represents a potentially important framework for improving HIV-related outcomes in this population. We sought to explore cognitive and behavioral dimensions of resilience and their correlates among Y-GBMSM to gain insights to inform future interventions

The PRS Rainbow Classification for Assessing Postbariatric Contour Deformities

Background: There is a need for a reliable classification system to grade contour deformities and to inform reimbursement of body contouring surgery after massive weight loss. We developed the PRS Rainbow Classification, which uses select photographs to provide standardized references for evaluating patient photographs, to classify contour deformities in postbariatric patients. To assess the reliability of the PRS Rainbow Classification to classify contour deformities in massive weight loss patients. Methods: Ten independent experienced plastic surgeons, 7 experienced medical advisors of the healthcare insurance company, and 10 laypersons evaluated 50 photographs per anatomical region (arms, breast, abdomen, and medial thighs). Each participant rated the patient photographs on a scale of 1-3 in an online survey. The inter-observer and the intra-observer reliabilities were determined using intra-class correlation coefficients (ICCs). The ICC analyses were performed for each anatomical region. Results: Inter-observer reliability was moderate to good in the body regions "arms," "abdomen," "medial thighs," with mean ICC values of 0.678 [95% confidence interval (CI), 0.591-0.768], 0.685 (95% CI, 0.599-0.773), and 0.658 (95% CI, 0.569-0.751), respectively. Inter-observer reliability was comparable within the 3 different professional groups. Intra-observer reliability (test-retest reliability) was moderate to good, with a mean overall ICC value of 0.723 (95% CI, 0.572-0.874) for all groups and all 4 body regions. Conclusions: The moderate to good reliability found in this study validates the use of the PRS Rainbow Classification as a reproducible and reliable classification system to assess contour deformities after massive weight loss. It holds promise as a key part of instruments to classify body contour deformities and to assess reimbursement of body contouring surgery

A system science perspective on burn-out: development of an expert-based causal loop diagram

IntroductionBurn-out leads to reduced worker well-being, long-term absenteeism, and high costs for employers and society. Determinants at different levels may affect burn-out in an interrelated and dynamic manner. The aim of the present study was to apply a broader systems perspective by exploring and visualizing the complex system of determinants at different levels (living conditions, working conditions, and societal developments) underlying the prevalence of burn-out in the Netherlands.MethodsDuring three group model building (GMB) sessions with in total eight experts on workers’ mental health, a causal loop diagram (CLD) was developed and relevant feedback loops were identified. For the selection of determinants to be included in the CLD a recently published overview of determinants on burn-out at different levels was used. Experts could also add factors that were not listed in the overview.ResultsThe final CLD consists of 20 factors and depicts a central position of working conditions. Societal developments (e.g., access to mental health care, size of the working population, rougher social climate, etc.) were mostly located at the outside of the CLD and barely integrated in feedback loops. Several reinforcing feedback loops resulting in an increase of the prevalence of burn-out were identified in which the factors (very) high workload, imbalance between work and private life, and insufficient recovery time play an important role. Also, several balancing loops were found that visualize the crucial role of functional support from supervisors to prevent burn-out among workers.DiscussionApplying a broader systems perspective, including determinants at different levels, offers new insights into dynamic feedback loops that contribute to the prevalence of burn-out. Supervisors, amongst others, have a considerable impact on the system underlying the high prevalence of burn-out and may therefore contribute to its prevention. Even though societal developments were less integrated in feedback loops, they might be considered drivers of existing feedback loops. The results from this study confirm that determinants at various levels underly the prevalence of burn-out. To be able to address the diversity of determinants underlying a high prevalence of burn-out, a complex system approach can be helpful

Not the Root of the Problem-Hair Cortisol and Cortisone Do Not Mediate the Effect of Child Maltreatment on Body Mass Index.

BACKGROUND: Experiencing maltreatment during childhood exerts substantial stress on the child and increases the risk for overweight and obesity later in life. The current study tests whether hair cortisol-a measure of chronic stress-and its metabolite cortisone mediate the relation between abuse and neglect on the one hand, and body mass index (BMI) on the other. METHOD: The sample consisted of 249 participants aged 8 to 87 years (M = 36.13, SD = 19.33). We collected data on child abuse and neglect using questionnaires, measured cortisol and cortisone concentrations in hair, and BMI. In a structural model, the effects of abuse and neglect on hair cortisol, hair cortisone, and BMI were tested, as well as the covariance between hair cortisol and BMI, and hair cortisone and BMI. RESULTS: Within the sample, 23% were overweight but not obese and 14% were obese. Higher levels of experienced abuse were related to higher cortisone concentrations in hair (β = 0.24, p < .001) and higher BMI (β = 0.17, p =.04). Neglect was not related to hair cortisol, hair cortisone, or BMI. Hair cortisol and cortisone did not mediate the association between maltreatment, and BMI. Sensitivity analyses demonstrate the same pattern of results in a subsample of adult participants currently not living with their parents. However, in younger participants who were still living with their parents, the associations between abuse and cortisone (β = 0.14, p =.35) and abuse and BMI (β = 0.02, p =.92) were no longer significant. CONCLUSION: These findings confirm that experiencing abuse is related to higher BMI but suggest that hair cortisol and cortisone are not the mechanism underlying the association between child maltreatment and BMI. This is the first study to show abuse may be associated to elevated concentrations of hair cortisone-evidence of long-term alterations in chronic stress levels. Future research may benefit from exploring the effects of maltreatment on weight gain in longitudinal designs, including measures of other potential mediators such as eating as a coping mechanism, and more direct indicators of metabolic health