Friction and wear performance analysis of hydrofluoroether-7000 refrigerant as lubricant

The disquiet about global warming has triggered the formulation and introduction of new generation of refrigerants. Hydrofluoroethers (HFEs) are within the family of newly developed environmentally friendly refrigerants with a wide range of application areas. Hydrofluoroethers reportedly have better heat transfer and thermodynamic properties. In addition to an understanding and knowledge of the thermodynamic properties of refrigerants, it is essential to understand the tribological properties of refrigerants within the context of sustainable development. Tribo-performance of refrigerants applied in refrigeration, air-conditioning and energy systems directly influences the durability, reliability and cost effectiveness of the system. HFE-7000 has considerable potential for engineering applications in green energy and low carbon technologies. In this research, a detailed investigation has been performed to assess friction and wear performance of HFE-7000 (HFE-347mcc3). HFE-7000 has been employed as lubricants. Experimental results indicate the formation of tribo-films on the topmost surfaces. Energy-Dispersive X-ray Spectroscopic (EDS) and X-ray Photoelectron Spectroscopic (XPS) analyses on the tested samples revealed significant presence of oxygenated and fluorinated anti-wear tribo-films. These oxygen and fluorine containing tribo-layers prevent metal to metal contact and contribute to the reduction of friction and wea

FMRepS: Pengurusan aduan kerosakan di Kolej Kediaman Perwira UTHM

Kolej Kediaman Perwira berhadapan dengan masalah merekod aduan kerosakan dan menyimpan butiran berkenaan pelajar yang semakin bertambah. Sehingga kajian ini dilakukan, jumlah penghuni sudah melebihi 500 orang. Begitu juga dengan aduan kerosakan yang diterima oleh pihak pengurusan kolej dari penghuni juga turut meningkat. Hal ini meresahkan staf Kolej Kediaman Perwira kerana pertambahan aduan bermakna bertambahnya penggunaan kertas dan dikhuatiri meningkatkan kos pengurusan Kolej Kediaman Perwira. Oleh yang demikian, Facilities Management Report System (FMRepS) telah dibangunkan bagi mengurangkan beban pihak pengurusan kolej dan yang lebih penting ialah memudahkan dan mencepatkan proses aduan kerosakan seperti yang disasarkan matlamat utama sistem. Sistem ini merekod segala butiran pelajar dan aduan yang ingin dibuat boleh dilakukan secara dalam talian tanpa perlu ke pejabat pengurusan Kolej Kediaman Perwira. Pembangunan FMRepS adalah berdasarkan Model Air Terjun dan menggunakan perisian Adobe Macromedia Dreamweaver, Adobe Photoshop dan MySQL sebagai pangkalan data untuk mencapai dan menyimpan data. Pemantauan telah dilakukan di Kolej Kediaman Perwira untuk melihat penggunaan kertas setelah FMRepS diimplemen di kolej. Hasil kajian menunjukkan FMRepS mampu mengurangkan kos kertas dan juga masa memproses aduan kerosakan. Ini menjadikan urusan aduan menjadi lebih mudah dan lebih efektif di Kolej Kediaman Perwira

Analysis of Simvastatin using a Simple and Fast High Performance Liquid Chromatography-Ultra Violet Method: Development, Validation and Application in Solubility Studies

Purpose: To develop and validate an accurate, rapid and reproducible reversed-phase high performance liquid chromatography (RP-HPLC) analytical method for the lipid lowering drug, simvastatin, and to apply the developed method to study the solubility of the drug in various oils andsurfactants.Methods: Isocratic RP-HPLC system with a UV-vis detector, and a column with dimensions 4.6 mm x 150 mm and 5ì particle size, was employed. The mobile phase consisted of methanol and 0.01M KH2PO4 phosphate buffer (80:20) at pH 5.5 adjusted with phosphoric acid (2M) and pumped at a flow rate of 1 ml/min. Validation parameters, viz, limit of detection (LOD), limit of quantification (LOQ) linearity, accuracy, precision, and sensitivity, were established. Solubility study was performed in various oils and surfactants at 25°C and the developed HPLC method was applied to analyze all samples.Results: The developed HPLC method showed good linearity (R2 = 0.9958 ± 0.0040. The intra- and inter-day % accuracy was more than 98 %. LOQ and LOQ were 0.160 and 0.484 ìg/ml respectively. Simvastatin showed the highest solubility in sesame oil (15 mg/ml) and in Tween 80 (11 mg/ml) at 25oC.Conclusion: An accurate, rapid and robust HPLC-UV method has been developed, validated and applied successfully to determine the solubility of simvastatin in oils.Keywords: Simvastatin, Validation, Solubility, Sesame oil, Tween 80

Solubility and Permeability Studies of Aceclofenac in Different Oils

Purpose: To measure the extent of solubility of the lipophilic drug,   aceclofenac, in 13 oils as well as its in vitro permeability from these oils in order to develop optimized topical microemulsion and  microemulsion-based gel for improved bioavailability.Methods: UV spectrophotometeric method was used at the wavelength of 276 nm to measure the dissolved quantity of aceclofenac in each of the oils (almond oil, oleic acid, castor oil, paraffin oil, cinnamon oil, clove oil, canola oil, sesame oil, isopropyl myristate (ipm), sunflower oil, corn oil, coconuts oil and eucalyptus oil) at 25 °C. The in-vitro permeability of aceclofenac in each of these oils was determined at 32 ± 0.5 °C using Franz diffusion cell with phosphate buffer (pH 7.4) as medium with 0.45ì cellulose acetate membrane. The solubility and permeability of aceclofenac were compared with the hydroalcoholic solution of aceclofenac.Results: The highest solubility values of 9.153 and 8.560 mg/ml for  aceclofenac were obtained with almond oil and oleic acid, respectively (p < 0.05). However the solubility and permeability of aceclofenac in hydro-alcoholic solution were 150.65 mg/ml and 14.91± 0.05 ìg/cm2/h,  respectively. Aceclofenac also showed higher permeability values (1.45± 0.04 and 1.21 ± 0.06) in almond oil and oleic acid, respectively, than in the other oils (p < 0.05).Conclusion: These findings show that almond oil and oleic acid are  promising vehicles for aceclofenac as its enhanced solubility and  permeability in these vehicles are suggestive of improved bioavailability.Keywords: Aceclofenac, Almond oil, Solubility; Permeability, Oleic acid, Bioavailability

Improvement measures to achieve sustainable construction labor performance

Construction industry is the largest industrial employer of the world. However, construction labor suffers from declining productivity, job satisfaction and wellbeing. Given its volume and labor extensiveness, measures undertaken to improve labor sustainability of the construction industry would have high impact for the future. To improve the sustainability of labor performance, this paper suggests decision-making measures at the strategic, tactical, and operational levels. Data is generated through targeted interviews of the top management of the five biggest Norwegian construction contractors. The measures suggested by the interviewees are analyzed and complemented with theory through a systematic literature review, resulting in the development of 45 measures to achieve sustainable labor performance at strategic, tactical, and operational decision-making levels. Due to strict labor laws and regulations, some frequently reported measures in literature do not hold relevance to the Norwegian construction industry. However, the quality of data and unique position of the Norwegian construction industry magnifies its relevance to the global construction industry

Praktik pertambangan galian C perspektif Undang-undang Nmor. 3 tahun 2020 dan fiqh lingkungan hidup : studi kasus CV. Bumi Berlian di Desa Kemantren Kecamatan Paciran Kabupaten Lamongan

Memanfaatkan sumber daya alam yang begitu melimpah salah satunya batu kapur, termasuk dalam kategori bahan galian C, yang mana cara memperolehnya dengan melakukan pertambangan seperti aktifitas yang dilakukan oleh CV. Bumi Berlian. Sementara dampak yang dtimbulkan aktifitas tersebut tentunya kerusakan lingkungan, sementara lokasi pertambangan itu sendiri berdekatan dengan beberapa pemukiman warga. Tidak hanya itu seharusnya pertambangan tersebut memberikan manfaat secara berkelanjutan sebagai penunjang perekonomian tetapi justru sebaliknya. Berdasarkan latar belakang tersebut, skripsi ini membahas dua rumusan masalah yaitu tinjauan Undang-undang No. 3 Tahun 2020 tentng Pertambangan Mineral dan Batubara dan fiqh lingkungan hidup terhadap dampak praktik pertambangan galian C. Penelitian ini merupakan penelitian normatif-empiris dengan data yang diperoleh melalui penelitian lapangan (field research). Adapun pendekatan yang digunakan adalah yuridis empiris sehingga data yang didapatkan merupakan data kualitatif yang menghasilkan data diskriptif serta didukung dengan observasi, wawancara, dokumentasi. Penelitian ini berkesimpulan bahwa praktik pertambangan galian C tersebut terdapat pelanggaran terhadap Undang-undang yeng berlaku. dampak negatif bagi lingkungan sekitar. Sementara apabila dilihat dari fiqh lingkungan kegiatan tersbut juga terdapat madharat bagi linkungan sekitar

Exploring the role of antecedents of product innovativeness and corporate social responsibility in extending customer citizenship behavior

In recent times, enhancing and extending the customer base is possible when organizations increase customer citizenship behavior among their consumers. Since the customers are much aware of firms’ social and environmental contributions thus, organizations take adequate measures to improve their product innovativeness and corporate social responsibility. Hence the current study is designed to ascertain the role of Corporate Social Responsibility (CSR) and product innovativeness in patronizing Customer Citizenship Behavior. Based on the survey research design, the current study applies structural equation modeling using Partial Least squares on the data set of 453 respondents. The results revealed that all proposed hypotheses were significant and positive. These findings imply that the service providers and manufacturers should increase transparency in the communication process through which CSR and innovativeness are effectively communicated to the customers, eventually assisting them in increasing their Customer Citizenship Behavior among customers. These results offer valuable policy insights

Sustainable green nanoadsorbents for remediation of pharmaceuticals from water and wastewater: A critical review

In the last three decades, pharmaceutical research has increased tremendously to offer safe and healthy life. However, the high consumption of these harmful drugs has risen devastating impact on ecosystems. Therefore, it is worldwide paramount concern to effectively clean pharmaceuticals contaminated water streams to ensure safer environment and healthier life. Nanotechnology enables to produce new, high-technical material, such as membranes, adsorbent, nano-catalysts, functional surfaces, coverages and reagents for more effective water and wastewater cleanup processes. Nevertheless, nano-sorbent materials are regarded the most appropriate treatment technology for water and wastewater because of their facile application and a large number of adsorbents. Several conventional techniques have been operational for domestic wastewater treatment but are inefficient for pharmaceuticals removal. Alternatively, adsorption techniques have played a pivotal role in water and wastewater treatment for a long, but their rise in attraction is proportional with the continuous emergence of new micropollutants in the aquatic environment and new discoveries of sustainable and low-cost adsorbents. Recently, advancements in adsorption technique for wastewater treatment through nanoadsorbents has greatly increased due to its low production cost, sustainability, better physicochemical properties and high removal performance for pharmaceuticals. Herein, this review critically evaluates the performance of sustainable green nanoadsorbent for the remediation of pharmaceutical pollutants from water. The influential sorption parameters and interaction mechanism are also discussed. Moreover, the future prospects of nanoadsorbents for the remediation of pharmaceuticals are also presented