2,410 research outputs found
Science in the Third Dimension of R&D
We study a Schumpeterian model of long-run growth with endogenous fertility and with three interacting dimensions of innovation. Scientific research is the fundamental dimension of innovation that creates new technological knowledge. This is allocated over new working prototypes in the horizontal dimension. New firms finance scientific research by obtaining the property rights of new working prototypes, and existing firms invest in developing the blueprint mode of working prototypes into the more productive modes of production in the vertical dimension. Balanced growth in the standards of living is fully endogenous without scale effects, and a new parameter, i.e., the elasticity of scientific knowledge with respect to existing collective scientific knowledge, nonlinearly accelerates long-run growth. With exogenous population growth, the model generates a semi-endogenous result due to the endogenously determined bound on technological opportunity.Science; Technology; Blueprints; R&D; Endogenous Fertility
Statutory auditor's role in corporate social and environmental reporting
The social and environmental audit practice is regarded as an effective mechanism for adding accuracy and credibility to the corporate social responsibility reports. In civilised societies, auditing is viewed as an evaluative tool for enhancing corporate accountability and transparency (Power, 1999; Owen and Humphrey, 2000; Sikka et. al, 1998; Smith et. al, 2011; Perego and Kolk, 2012). Throughout the past few decades, previous investigatory studies have provided a critical assessment of the evolution of social audit practices (for example, Gray, 2000; 2007; O’Dwyer and Owen, 2005; 2007; Bebbington and Thomson, 2007; Manetti and Toccafondi, 2012; Bepari and Mollik, 2016; Canning et. al, 2019). However, these studies offered little evidence on issues related to the impact of social audit services on the professional independence and ethic of auditors, and the role of religious and cultural values in shaping the nature of the social audit engagements. Furthermore, there is also a paucity in the prior literature in investigating critical issues, such as the lack of consistency in social and environmental audit practices. Moreover, the influence of socio-environmental factors on the views of stakeholders on social auditing remains largely unaddressed in the mainstream literature.
Most studies in the relevant literature examined the social and environmental audit phenomenon from a Western perspective, leaving several open-ended questions and unresearched issues about the social audit practices in non-Western contexts. The present research aims to fill the gap in the literature by highlighting sustainability audits in the emerging economies from an Islamic angle, taking Saudi Arabia as a model. In doing so, the study sought to scrutinise the social audit phenomenon and elicit viewpoints from audit providers and relevant stakeholders, embracing the interpretivist methodology to help in gaining insights from this exploratory examination. Particularly, the study selected a triangulation of mixed methods to collect data through content analysis of audit reports, and semi-structured interviews with statutory auditors and individual stakeholders. Finally, the empirical findings were analysed and interpreted with the consideration of the three theoretical constructs (audit, legitimacy, and stakeholder theories).
The interviewed auditors claimed that social and environmental audit services would benefit the audit firms, the companies, and the Saudi Arabian society. However, some interviewees expressed concerns about various risks associated with the ways social and environmental audits are currently exercised. Although the audit of corporate social responsibility reports helps to identify risks in corporate governance systems, it may jeopardise the impartiality and ethics of audit providers. Consequently, the social and environmental audit engagements may pose a reputational risk to the audit firm.
Similarly, statutory auditors expressed opposing views about engaging stakeholders in the social and environmental audit processes. While some interviewees admitted that the audit of stakeholder engagements in client companies' social responsibility processes is a daunting, costly and valueless task for Saudi Arabian audit firms, others supported that audit procedure as an accountability and transparency enabler. Nevertheless, there are several problematic issues associated with stakeholder engagement reporting audits. Obstacles to the auditing of stakeholder engagement include, among others, dealing with unreliable evidence, engaging the irrelevant stakeholders, and the inability to assess the stakeholder materiality and relevance. Also, the statutory auditors offered a collective opinion that regarded the accurate representation of stakeholders' views on companies' social performance as a quite challenging and unattainable goal within the Saudi cultural boundaries.
On the other hand, the interviewees from stakeholder groups gave a general satisfactory impression of the growing, albeit slowly, social audit performance. The participated stakeholders recognised and appreciated the importance of the voluntary contribution of statutory auditors to the Saudi Arabian business environment through their independent verification of corporate social and environmental responsibility activities and statements.
Whereas findings from the content analysis of sixty audit reports revealed a high tendency of statutory auditors to integrate the outcome of social and environmental audit processes with that of the traditional financial auditing within single audit statements. The observation showed also an overwhelming reliance on accountancy-based approaches of generally accepted financial auditing standards in Saudi Arabia, ISA, or the ISAE 3000 in the audits of corporate social and environmental reports. Stakeholder engagements in the social audits were noticed in only one audit report, which illustrated a limited range of assurance on a company-stakeholder dialogue.
Although the audit of corporate social and sustainability reports is not mandated in Saudi Arabia, the statutory auditors' voluntary role in ensuring the validity of corporate social responsibility statements is seen as an acceptable act whereby auditors can boost their social legitimacy. From an Islamic perspective, the notion of corporate social and environmental responsibility is strongly encouraged for Islamically permitted or Halal purposes (Dusuki, 2008; Elasrag, 2015). Hence, the provision of sustainability audit services to improve the quality of corporate social reporting and discharge organisational accountability can be viewed as an Islamic permitted act.
Overall, social audit exercises in Saudi Arabia are still at an early stage and necessitate substantial improvements
Effect of dissolved oxygen and chemical oxygen demand to nitrogen ratios on the partial nitrification/denitrification process in moving bed biofilm reactors
Partial nitrification was reported to be technically feasible and economically favorable, especially for wastewater with high ammonium concentration or low C/N ratio. In this study, the effect of dissolved oxygen (DO) and influent ratio of chemical oxygen demand to nitrogen (COD/N) ratio on biological nitrogen removal from synthetic wastewater was investigated. Experiments were conducted in moving bed biofilm reactors (MBBRs) on partial nitrification process in pilot-plant configuration for 300 days. DO levels were changed from 0.04 to 0.12 and 0.42 to 3.4 mg/l in the anoxic (R1) and aerobic (R2) reactors, respectively. The optimum DO for partial nitrification was between 1-1.5 mg/l in the aerobic reactor (R2). Influent COD/N ratios between 20 and 2 g COD/g-N were tested by changing the nitrogen loading rate (NLR) supplied to the pilot plant. During operational conditions when the DO concentration in aerobic reactor was above 1 mg/l, near complete organic carbon removal occurred in the total MBBRs system. The effluent total nitrogen concentration in the operational conditions (1.7-2.1 mg O2/l and NH+ 4-N=35.7 mg N/l) was obtained in the range of 0.85-2 mg/l. The highest nitrite accumulation (50%- 52%) took place at the DO concentration of 1-1.5 mg/l and increased with decreasing COD/N ratio in aerobic reactor (R2). This study showed that the average nitrification rate at various COD/N ratios is about 0.96 gN/m2 per day while the maximum nitrification rate is about 2 gN/m2 per day at COD/N ratios lower than 6. The experimental COD/N ratio for denitrification was close to complete sum of NO2 - and NO3 - (NOx) removal efficiency (about 99%) at COD/N ratio equal 14 in the operational conditions in the anoxic reactor (R1)
Publisher's Note: "Solution processed multilayer polymer light-emitting diodes based on different molecular weight host" (vol 109, 074516, 2011)
Solution processed multilayer polymer light-emitting diodes (PLEDs) based on different molecular weight host have been investigated. A PLED based on high molecular weight poly (vinyl carbazole) PVKH and low molecular weight poly (vinyl carbazole) PVKL, doped with iridium, tris(2-phenylpyidine) Ir(ppy)3 as a host-guest emitting layer (EML), shows a dramatic increase in device efficiency. When the PVKH was used as a hole transport electron blocking layer (HT-EBL), effective electron blocking was achieved, which leads to an increase exciton population in the phosphorescent zone. The use of low molecular weight PVKL as a host material in the top layer prevents barrier formation for hole transport from the poly(3,4-ethylenedioxy-thiophene) (PEDOT)–EBL to the EML. External quantum efficiency of 11%, current efficiencies of 38 cd/A, power efficiency of 13 lm/W and brightness of 7000 cd/m2, were obtained. The effect of the PVKH layer on the electrical and optical device characteristics was investigated. Simulation of the optical outcoupling using SETFOS 3.1 software is in agreed with the observed results and allowed us to predict the emissive dipole location and distribution in the EML layer. The effect of the PVKH on the exciton quenching by the electrodes was also investigated using time resolved fluorescence photon counting, which indicates weak exciton quenching by the PEDOT layer and the device enhancement predominantly achieved by exciton confinement in the emissive layer
Electrophoretic serum protein fractions in dwarf and normal layer hens and their correlations with productive traits
Effect of Cytotoxicity of Pegylated Liposomal Recombinant Human Erythropoietin-alfa on Neuroblastoma Cell Line SHSY5Y
Purpose: To evaluate the cytotoxic effect of pegylated liposomal Recombinant Human Erythropoietinalfa (rHuEPO) nanoparticles synthesized by reverse phase evaporation technique on SH-SY5Y cell line.Methods: To prepare the nanoparticles of the drug, rHuEPO, PEG3000, cholesterol andphosphatidylcholine were dissolved in buffer phosphate. The characteristics of the synthesized nanoparticles were determined by a zetasizer. Encapsulation efficiency, drug loading efficiency and drug release pattern were evaluated spectrophotometrically. The cytotoxicity effect of pegylated nanoliposomal rHuEPO was evaluated on SH-SY5Y cell line by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay.Results: Size and zeta potential of pegylated nanoliposomal drug and blank pegylated nanoliposomes were 571 ± 6.8 nm, -16.5 mV; 280 ± 4.71 nm and -27.1 mV, respectively. Encapsulation and drug loading efficiency were 89 ± 3.9 % and 0.8 ± 0.012 %, respectively. Drug release data indicate that 17 % of rHuEPO was released from pegylated liposomal nanoparticles over a period of 30 h. The difference in cytotoxicity between the free drug (IC50 = 110.1 ± 3.1 μg/ml) and nanodrug (IC50 = 87.2 ± 2.3 μg/ml) was statistically significant (p ˂ 0.05).Conclusion: This study shows that pegylated nanoliposomal rHuEPO has a powerful cytotoxic effect on SH-SY5Y cell line and is therefore a suitable alternative to the standard therapy, rHuEPO, for the chemotherapy of neuroblastoma.Keywords: Recombinant Human Erythropoietin-alfa, Cytotoxicity, Drug delivery, Liposome, Reverse phase evaporation, SH-SY5Y cell lin
Optimisation of panel component regions subject to hot stamping constraints using a novel deep-learning-based platform
The latest hot stamping processes can enable efficient production of complex shaped panel components with high stiffness-to-weight ratios. However, structural redesign for these intricate processes can be challenging, because compared to cold forming, the non-isothermal and dynamic nature of these processes introduces complexity and unfamiliarity among industrial designers. In industrial practice, trial-and-error approaches are currently used to update non-feasible designs where complicated forming simulations are needed each time a design change is made. A superior approach to structural redesign for hot stamping processes is demonstrated in this paper which applies a novel deep-learning-based optimisation platform. The platform consists of the interaction between two neural networks: a generator that creates 3D panel component geometries and an evaluator that predicts their post-stamping thinning distributions. Guided by these distributions the geometry is iteratively updated by a gradient-based optimisation technique. In the application presented in this paper, panel component geometries are optimised to meet imposed constraints that are derived from post-stamping thinning distributions. In addition, a new methodology is applied to select arbitrary geometric regions that are to be fixed during the optimisation. Overall, it is demonstrated that the platform is capable of optimising selective regions of panel component subject to imposed post-stamped thinning distribution constraints
Performance of High-volume Fly Ash Self-compacting Concrete Exposed to External Sulfate Attack
The high-volume fly ash concrete, HVFAC, could be defined as any concrete mix having fly ash content larger than 50 percent of the total cementitious materials content. Due to the availability of fly ash in large quantities globally with low cost, HVFAC could be considered as a solution for the environmental impact of Portland cements. In this study the durability of two high-volume fly ash self-compacting concrete, HVFASCC, mixes exposed to the effects of two sulfate aggressive solutions was investigated. The fly ash, class F, contents for these mixes were 50 and 60 percent by weight of Portland cement. The external sulfate attack was simulated by submerging the concrete specimens in 5 percent sodium and magnesium sulfate solutions separately for 240 days. Six mixes were produced for this purpose, they were: 2 reference mixes cured in water, 2 mixes submerged in Na2SO4 solution and 2 mixes submerged in MgSO4 solution. The testing program includes: slump flow, V-funnel, L-box, weight change, XRD and the strength tests: compressive, splitting and flexural strengths. The fly ash content has a positive effect on the rheology (workability) of all tested mixtures. In other words, increasing the cement replacement level from 50 to 60 percent has enhanced the filling ability, passing ability, and segregation resistance of the investigated SCC mixes. The test results show that the magnesium solution has the higher harmful effect on all mixes than the sodium solution. The replacements of Portland cement by the assigned percentages of fly ash have significantly increased the resistance of SCC to the external sulfate attack due to lime consuming reaction
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