297 research outputs found

    Pemanfaatan Hasil Pirolisis Limbah Ban Bekas Sebagai Bahan Pelunak Untuk Pembuatan Barang Jadi Karet

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    Perkembangan industri automotif yang pesat menjadikan permintaan yang besar terhadap ban kendaraan. Dampak negatif yang dihasilkan adalah melimpahnya limbah ban bekas. Sebagai USAha untuk memanfaatkan limbah ban bekas, telah dilakukan penelitian untuk merubah limbah ban bekas menjadi bahan pelunak barang jadi karet dengan proses pirolisis. Pirolisis dilakukan pada suhu 5000C selama 3 jam, menghasilkan cairan pirolisat dengan nilai berat jenis spesifik 1,0139, viskositas kinematis pada 2100F 7,063 cst, titik tuang -60C dan titik nyala 156,50C. Hasil uji sifat fisika vulkanisat menunjukkan bahwa pirolisat dari ban bekas dapat digunakan sebagai bahan pelunak barang jadi karet yang ditunjukkan dari hasil uji yang tidak berbeda nyata antara vulkanisat yang mengandung bahan pelunak kontrol dengan bahan pelunak dari pirolisat ban bekas. Diterima : 19 Februari 2013; Disetujui : 22 Maret 2013 How to Cite : Falaah, A. F., Cifriadi, A., & Maspanger, D. R. (2013). Pemanfaatan hasil pirolisis limbah ban bekas sebagai bahan pelunak untuk pembuatan barang jadi karet. Jurnal Penelitian Karet, 31(2), 149-158. Retrieved from http://ejournal.puslitkaret.co.id/index.php/jpk/article/view/14

    Pemekatan Lateks Kebun Secara Cepat Dengan Proses Sentrifugasi Putaran Rendah

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    Tujuan dari penelitian ini adalah untuk mempelajari kombinasi proses pendadihan dan sentrifugasi, untuk meningkatkan kecepatan pendadihan dengan menggunakan mesin sentrifugasi kecepatan rendah. Lateks pekat adalah salah satu jenis produk komersial dari industri karet dan masih diproduksi oleh pabrik besar, umumnya dibuat dari mesin sentrifugasi yang biaya investasinya mahal. Hal inilah yang menjadi hambatan bagi industri kecil untuk terjun dalam industri lateks pekat. Untuk memproduksi lateks pekat dari lateks kebun dapat dilakukan dengan proses sentrifugasi putaran tinggi (9000-15000 rpm) dan pendadihan. Lateks dadih adalah lateks pekat, dibuat dengan menggunakan bahan pendadih misalnya CMC dan alginat dalam tangki secara batch selama 1-2 minggu dan proses pendadihan ini kecepatan pemisahannya sangat lambat, sehingga membutuhkan waktu yang lama, akibatnya lateks pekat yang diproduksi dengan teknik pendadihan tidak populer di industri. Dalam penelitian ini sebuah mesin sentrifugasi didisain sederhana dan diharapkan layak digunakan oleh industri kecil menengah, digerakkan dengan motor 5 HP dengan kecepatan maksimum 5000 rpm dan mempunyai kapasitas sekitar 5-6 liter lateks kebun. Untuk memproduksi lateks dadih sekitar 5 liter lateks kebun per jam, bahan pendadih CMC ditambahkan ke lateks kebun dengan dosis 0 sampai 0,2%. Waktu sentrifugasi divariasikan selama 0 sampai 60 menit pada kecepatan 5000 rpm. Hasil penelitian menunjukkan, kondisi optimum untuk memperoleh Kadar Karet Kering di atas 60% diperoleh pada dosis CMC hanya 0,1% dengan waktu sentrifugasi selama 45 menit. Diterima : 25 April 2014; Direvisi : 18 Mei 2014; Disetujui : 9 Juli 2014 How to Cite : Prastanto, H., Falaah, A. F., & Maspanger, D. R. (2014). Pemekatan lateks kebun secara cepat dengan proses sentrifugasi putaran rendah. Jurnal Penelitian Karet, 32(2), 181-188. Retrieved from http://ejournal.puslitkaret.co.id/index.php/jpk/article/view/16

    Pembelajaran Savir (Somatic, Auditory, Visual, Intellectual, dan Repetition) dalam Mempertahankan Retensi Siswa Pokok Bahasan Asas Black dan Pemuaian

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    Tujuan penelitian ini adalah untuk mengetahui gambaran daya tahan retensi siswa pada pokok bahasan asas black dan pemuaian dengan menerapkan pembelajaran SAVIR. Penelitian ini juga melihat bagaimana keterlaksanaan pembelajaran SAVIR. Penelitian ini menggunakan desain penelitian One Group Pretest-Posttest Design dengan pemberian posttest sebanyak tiga kali dalam selang waktu antara posttest beberapa hari. Sampel dalam penelitian ini adalah siswa pada kelas X di salah satu SMA Negeri di Kecamatan Payakumbuh, Sumatera Barat dengan jumlah 28 orang. Hasil penelitian menunjukkan bahwa keterlaksanaan pembelajaran meningkat pada setiap pertemuan. Diperoleh y= 1,05e-0,01x pada grafik eksponensial daya tahan retensi siswa pada pokok bahasan asas black dan y=e-0,01x. pada pokok bahasan pemuaian. Hasil penelitian ini menunjukkan bahwa penerapan pembelajaran SAVIR dapat mempertahankan retensi siswa pada pokok bahasan asas black dan pemuaian

    Private hospital energy performance benchmarking using energy audit data: an Italian case study

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    The increased focus on energy efficiency, both at the national and international levels, has fostered the diffusion and development of specific energy consumption benchmarks for most relevant economic sectors. In this context, energy-intensive facilities, such as hospitals and health structures, represent a unique case. Indeed, despite the high energy consumption of these structures, scientific literature lacks the presence of adequate energy performance benchmarks, especially in regard to the European context. Thus, this study aimed at defining energy benchmark indicators for the Italian private healthcare sector using data collected from the Italian mandatory energy audits according to Art.8 EU Directive 27/2012. The benchmark indicators’ definition was made using a methodology proposed by the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). This methodology provided the calculation of specific energy performance indicators (EnPIs) by considering the global energy consumption of the different sites and the sector’s relevant variables. The results obtained were compared with those obtained from a consolidated but more complex methodology: the one envisaged by the Environmental Protection Agency. The results obtained allowed us to validate the reliability of the proposed methodology, as well as the validity and future usability of the calculated indicators. Relying on a significant database containing actual data from recent energy audits, this study was thus able to provide an up-to-date and reliable benchmark for the private healthcare sector

    Harmonic oscillator with nonzero minimal uncertainties in both position and momentum in a SUSYQM framework

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    In the context of a two-parameter (α,β)(\alpha, \beta) deformation of the canonical commutation relation leading to nonzero minimal uncertainties in both position and momentum, the harmonic oscillator spectrum and eigenvectors are determined by using techniques of supersymmetric quantum mechanics combined with shape invariance under parameter scaling. The resulting supersymmetric partner Hamiltonians correspond to different masses and frequencies. The exponential spectrum is proved to reduce to a previously found quadratic spectrum whenever one of the parameters α\alpha, β\beta vanishes, in which case shape invariance under parameter translation occurs. In the special case where α=β0\alpha = \beta \ne 0, the oscillator Hamiltonian is shown to coincide with that of the q-deformed oscillator with q>1q > 1 and its eigenvectors are therefore nn-qq-boson states. In the general case where 0αβ00 \ne \alpha \ne \beta \ne 0, the eigenvectors are constructed as linear combinations of nn-qq-boson states by resorting to a Bargmann representation of the latter and to qq-differential calculus. They are finally expressed in terms of a qq-exponential and little qq-Jacobi polynomials.Comment: LaTeX, 24 pages, no figure, minor changes, additional references, final version to be published in JP

    Photoswitchable diacylglycerols enable optical control of protein kinase C.

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    Increased levels of the second messenger lipid diacylglycerol (DAG) induce downstream signaling events including the translocation of C1-domain-containing proteins toward the plasma membrane. Here, we introduce three light-sensitive DAGs, termed PhoDAGs, which feature a photoswitchable acyl chain. The PhoDAGs are inactive in the dark and promote the translocation of proteins that feature C1 domains toward the plasma membrane upon a flash of UV-A light. This effect is quickly reversed after the termination of photostimulation or by irradiation with blue light, permitting the generation of oscillation patterns. Both protein kinase C and Munc13 can thus be put under optical control. PhoDAGs control vesicle release in excitable cells, such as mouse pancreatic islets and hippocampal neurons, and modulate synaptic transmission in Caenorhabditis elegans. As such, the PhoDAGs afford an unprecedented degree of spatiotemporal control and are broadly applicable tools to study DAG signaling

    Ethiopian indigenous goats offer insights into past and recent demographic dynamics and localadaptation in sub-Saharan African goats

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    Abstract Knowledge on how adaptive evolution and human socio‐cultural and economic interests shaped livestock genomes particularly in sub‐Saharan Africa remains limited. Ethiopia is in a geographic region that has been critical in the history of African agriculture with ancient and diverse human ethnicity and bio‐climatic conditions. Using 52K genome‐wide data analysed in 646 individuals from 13 Ethiopian indigenous goat populations, we observed high levels of genetic variation. Although runs of homozygosity (ROH) were ubiquitous genome‐wide, there were clear differences in patterns of ROH length and abundance and in effective population sizes illustrating differences in genome homozygosity, evolutionary history, and management. Phylogenetic analysis incorporating patterns of genetic differentiation and gene flow with ancestry modelling highlighted past and recent intermixing and possible two deep ancient genetic ancestries that could have been brought by humans with the first introduction of goats in Africa. We observed four strong selection signatures that were specific to Arsi‐Bale and Nubian goats. These signatures overlapped genomic regions with genes associated with morphological, adaptation, reproduction and production traits due possibly to selection under environmental constraints and/or human preferences. The regions also overlapped uncharacterized genes, calling for a comprehensive annotation of the goat genome. Our results provide insights into mechanisms leading to genome variation and differentiation in sub‐Saharan Africa indigenous goats

    Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

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    Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

    Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017 : a systematic analysis for the Global Burden of Disease Study 2017

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    Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data. Methods: We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting. Findings: Globally, for females, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and haemoglobinopathies and haemolytic anaemias in both 1990 and 2017. For males, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and tuberculosis including latent tuberculosis infection in both 1990 and 2017. In terms of YLDs, low back pain, headache disorders, and dietary iron deficiency were the leading Level 3 causes of YLD counts in 1990, whereas low back pain, headache disorders, and depressive disorders were the leading causes in 2017 for both sexes combined. All-cause age-standardised YLD rates decreased by 3·9% (95% uncertainty interval [UI] 3·1–4·6) from 1990 to 2017; however, the all-age YLD rate increased by 7·2% (6·0–8·4) while the total sum of global YLDs increased from 562 million (421–723) to 853 million (642–1100). The increases for males and females were similar, with increases in all-age YLD rates of 7·9% (6·6–9·2) for males and 6·5% (5·4–7·7) for females. We found significant differences between males and females in terms of age-standardised prevalence estimates for multiple causes. The causes with the greatest relative differences between sexes in 2017 included substance use disorders (3018 cases [95% UI 2782–3252] per 100 000 in males vs s1400 [1279–1524] per 100 000 in females), transport injuries (3322 [3082–3583] vs 2336 [2154–2535]), and self-harm and interpersonal violence (3265 [2943–3630] vs 5643 [5057–6302]). Interpretation: Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss. This study emphasises how global improvements in premature mortality for select conditions have led to older populations with complex and potentially expensive diseases, yet also highlights global achievements in certain domains of disease and injury. Funding: Bill & Melinda Gates Foundation
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