Studi Emisi Karbon Dioksida dari Tiga Jenis Lahan Gambut di Desa Tanjung Leban dan Sepahat Kecamatan Bukit Batu Kabupaten Bengkalis

The high concentration of carbon dioxide in the atmosphere is suspected as the main cause of global warming, therefore, the carbon balance is very important to investigate. At this time, tropical peatlands are used as agricultural cultivation and plantation, one of them is in Bengkalis, Riau Province. This study aimed to measure the concentration of CO2 based on the relationship of physical and chemical properties of peat. Measurements were performed on peatlands which have different vegetation cover, i.e. bush land, oil palm plantation, and secondary forest. The used method in this study are Infrared Gas Analyzer and Gas Chromatography. The average of obtained emissions based on the effect of water table, peat temperature, and pH (H2O) of bush land, oil palm plantation, and secondary forest are 497,4 ppm, 523,2 ppm, and 457,2 ppm, respectively

The Intermediate Luminosity Optical Transient SN 2010da: The Progenitor, Eruption and Aftermath of a Peculiar Supergiant High-mass X-ray Binary

We present optical spectroscopy, ultraviolet to infrared imaging and X-ray observations of the intermediate luminosity optical transient (ILOT) SN 2010da in NGC 300 (d=1.86 Mpc) spanning from -6 to +6 years relative to the time of outburst in 2010. Based on the light curve and multi-epoch SEDs of SN 2010da, we conclude that the progenitor of SN 2010da is a ~10-12 Msol yellow supergiant possibly transitioning into a blue loop phase. During outburst, SN 2010da had a peak absolute magnitude of M<-10.4 mag, dimmer than other ILOTs and supernova impostors. We detect multi-component hydrogen Balmer, Paschen, and Ca II emission lines in our high-resolution spectra, which indicate a dusty and complex circumstellar environment. Since the 2010 eruption, the star has brightened by a factor of ~5 and remains highly variable in the optical. Furthermore, we detect SN 2010da in archival Swift and Chandra observations as an ultraluminous X-ray source (L~6x10^{39} erg/s). We additionally attribute He II 4686 Angstrom and coronal Fe emission lines in addition to a steady X-ray luminosity of ~10^{37} erg/s to the presence of a compact companion.Comment: published; updated citations and other minor edit

Penggunaan Blok Persegi Termodifikasi Dan Trapesium Dalam Perencanaan Beton Mutu Tinggi Dan Sangat Tinggi

Tujuan dari penelitian ini adalah untuk mendapatkan tatacara perencanaan beton mutu tinggi dan sangat tinggi dengan menggunakan blok pendekatan persegi yang termodifikasi dan blok trapesium. Penelitian dimulai dengan studi literatur dan perhitungan luasan diagram interaksi tegangan regangan beton. Setelah itu dilakukan ekuivalensi antara luasan diagram interaksi tegangan regangan dan luasan blok pendekatan, kemudian diperoleh koefisien-koefisien penyesuaian. Langkah selanjutnya adalah menurunkan rumus yang mengandung koefisien penyesuaian untuk mendapatkan rasio tulangan perlu dan langkah yang terakhir adalah menyusun tata cara perencanaan beton bertulang mutu tinggi dan sangat tinggi. Mutu beton yang ditinjau dalam penelitian ini adalah beton dengan mutu 15 – 120 MPa. Untuk pendekatan persegi termodifikasi diperoleh koefisien penyesuaian β1 berkisar antara 0.68 sampai 0.98, dengan 0.68 merupakan nilai β1 untuk beton 120 MPa sedangkan 0.98 untuk beton 15 MPa. Nilai β1 tersebut adalah nilai yang aman karena telah sesuai dengan syarat nilai β1 menurut SNI 03-2847-2002 yaitu β1 ≥ 0.65.Untuk pendekatan trapesium diperoleh nilai koefisien α untuk penyesuaian luasan berkisar antara 0.16 sampai 0.63, sedangkan untuk koefisien penyesuaian titik berat (γ) berkisar antara 0.0061 sampai 0.0222. The purpose of the research is to obtained a design procedure for flexure design of high strength and ultra high strength concrete; using modified rectangular block and trapezoidal block approaches. Analytical and design equations were formulated for each of the approaches, then by equating area of the block with that of actual stress-strain diagram, and internal moment of the force of the block to that of the actual stress-strain diagram, characeristic coefficients of each aproach were determined and adjusted. The procedure was done on high and ultra-high strength concrete (fc' in the range of 15 to 120 MPa. The value of β1 ¬–coefficient for modified rectangular block approach was found to be in the range of 0.68 to 0.98, where 0.68 is β1 for 120 MPa and 0.98 for 15 MPa. These values are safe as it complies with the value required for it by SNI 03-2847-2002 namely that β1 ¬¬must be greater than 0.65. For the trapezoidal block approach there are two coefficients. They are α, coefficient for the area adjustment and γ, coefficient for the adjustment of center of mass. The research yielded that α is in the range of 0.16 to 0.63 and γ is in the range of 0.0061 to 0.0222. Design procedure was then prepared using each of the approach based on their respective characteristic coefficients

Right ventricular outflow tract velocity time integral-to-pulmonary artery systolic pressure ratio: a non-invasive metric of pulmonary arterial compliance differs across the spectrum of pulmonary hypertension.

Pulmonary arterial compliance (PAC), invasively assessed by the ratio of stroke volume to pulmonary arterial (PA) pulse pressure, is a sensitive marker of right ventricular (RV)-PA coupling that differs across the spectrum of pulmonary hypertension (PH) and is predictive of outcomes. We assessed whether the echocardiographically derived ratio of RV outflow tract velocity time integral to PA systolic pressure (RVOT-VTI/PASP) (a) correlates with invasive PAC, (b) discriminates heart failure with preserved ejection-associated PH (HFpEF-PH) from pulmonary arterial hypertension (PAH), and (c) is associated with functional capacity. We performed a retrospective cohort study of patients with PAH (n = 70) and HFpEF-PH (n = 86), which was further dichotomized by diastolic pressure gradient (DPG) into isolated post-capillary PH (DPG \u3c 7 mmHg; Ipc-PH, n = 54), and combined post- and pre-capillary PH (DPG ≥ 7 mm Hg; Cpc-PH, n = 32). Of the 156 patients, 146 had measurable RVOT-VTI or PASP and were included in further analysis. RVOT-VTI/PASP correlated with invasive PAC overall (ρ = 0.61, P \u3c 0.001) and for the PAH (ρ = 0.38, P = 0.002) and HFpEF-PH (ρ = 0.63, P \u3c 0.001) groups individually. RVOT-VTI/PASP differed significantly across the PH spectrum (PAH: 0.13 [0.010-0.25] vs. Cpc-PH: 0.20 [0.12-0.25] vs. Ipc-PH: 0.35 [0.22-0.44]; P \u3c 0.001), distinguished HFpEF-PH from PAH (AUC = 0.72, 95% CI = 0.63-0.81) and Cpc-PH from Ipc-PH (AUC = 0.78, 95% CI = 0.68-0.88), and remained independently predictive of 6-min walk distance after multivariate analysis (standardized β-coefficient = 27.7, 95% CI = 9.2-46.3; P = 0.004). Echocardiographic RVOT-VTI/PASP is a novel non-invasive metric of PAC that differs across the spectrum of PH. It distinguishes the degree of pre-capillary disease within HFpEF-PH and is predictive of functional capacity

Corticomotor responses to attentionally demanding motor performance: a mini-review

Increased attentional demand has been shown to reduce motor performance, leading to increases in accidents, particularly in elderly populations. While these deficits have been well documented behaviorally, their cortical correlates are less well known. Increased attention has been shown to affect activity in prefrontal regions of the cortex. However there have been varying results within past research investigating corticomotor regions, mediating motor performance. This mini-review initially discusses past behavioral research, before moving to studies investigating corticomotor areas in response to changes in attention. Recent dual task studies have revealed a possible decline in the ability of older, but not younger, adults to activate inhibitory processes within the motor cortex, which may be correlated with poor motor performance, and thus accidents. A reduction in cortical inhibition may be caused by neurodegeneration within prefrontal regions of the cortex with age, rendering older adults less able to allocate attention to corticomotor regions

Work-Related Mental Health and Job Performance: Can Mindfulness Help?

Work-related mental health issues such as work-related stress and addiction to work impose a significant health and economic burden to the employee, the employing organization, and the country of work more generally. Interventions that can be empirically shown to improve levels of work-related mental health – especially those with the potential to concurrently improve employee levels of work performance – are of particular interest to occupational stakeholders. One such broad-application interventional approach currently of interest to occupational stakeholders in this respect is mindfulness-based interventions (MBIs). Following a brief explication of the mindfulness construct, this paper critically discusses current research directions in the utilization of mindfulness in workplace settings and assesses its suitability for operationalization as an organization-level work-related mental health intervention. By effecting a perceptual-shift in the mode of responding and relating to sensory and cognitive-affective stimuli, employees that undergo mindfulness training may be able to transfer the locus of control for stress from external work conditions to internal metacognitive and attentional resources. Therefore, MBIs may constitute cost-effective organization-level interventions due to not actually requiring any modifications to human resource management systems and practises. Based on preliminary empirical findings and on the outcomes of MBI studies with clinical populations, it is concluded that MBIs appear to be viable interventional options for organizations wishing to improve the mental health of their employees