Enhanced LANDSAT images of Antarctica and planetary exploration

Since early in the LANDSAT program, black-and-white paper prints of band 7 (near infrared) of the LANDSAT multispectral scanner have been used extensively to prepare semicontrolled maps of Antarctica. Image-processing techniques are now employed to enhance fine detail and to make controlled image-mosaic maps in color. LANDSAT multispectral images of Antarctica help to expand our knowledge of extraterrestrial bodies by showing bare-ice areas as bright blue patches; on such patches meteorites tend to be concentrated and are collected. Many subtle flow features in Antarctic ice streams resemble features at the mouths of Martian outflow channels, which suggests that the channels also contained ice. Furthermore, flow lines in Antarctic ice sheets that merge with ice shelves resemble Martian flow features associated with dissected terrain along the Martian northern highland margin, and support the concept that ice was involved in the transport of material from the southern highlands to the northern lowland plains. In Antarctica, as on Mars, the virtual absence of fluvial activity over millions of years has permitted the growth of glacial and eolian features to unusually large sizes

Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.Comment: 15 pages, 3 figure

The female partners’ perspective on vasectomy in the central region of Ghana

Background: Vasectomy is one of the safest and inexpensive modern contraceptive methods but it remains relatively‘invisible’ in Ghana. Support of women may be a significant incentive in influencing their partners to adopt vasec- tomy.Objective: To examine the perspectives of women on vasectomy as a contraceptive option.Materials and Methods: A cross-sectional survey was conducted among 298 women accessing long-term or perma- nent family planning methods at health facilities in three selected districts in the Central Region of Ghana. Pearson’s Chi-square was used to test associations between variables and the attitudes of women towards vasectomy. A p-value of less than 0.05 was considered to be statistically significantResults: Awareness of vasectomy was low (32%). About 66% of the women who became aware of vasectomy during the study would prefer their partners to go for vasectomy compared with 50% of those who were aware prior to the study. Women who would either not prefer vasectomy or support their partner’s choice of vasectomy cited fear of impotency (39.6%). There was a statistically significant association (p<0.05) between ethnicity, previous contracep- tive use, awareness of male methods, and preference for vasectomy instead of bilateral tubal ligation (BTL). A statis- tically significant association (p<0.05) was also found between age of participant, duration of marriage, religious affiliation, and the willingness of women to support their partner’s choice of vasectomy.Conclusion: There is, therefore, the need for the involvement of women in the promotion of vasectomy through vigorous publicity and education.Funding: By authorsKeywords: vasectom , tubal, contraceptive agents, Ghana, sterilizatio

Review of errors in the issue of medical certificates of cause of death in a tertiary hospital in Ghana

Objective; Reliable mortality statistics are useful in determining national policies on preventive and interventional medicine. This study reviews, completed medical certificates of cause of death at the Cape Coast Teaching Hospital, in order to determine their accuracy and reliability.Methods: A one-year review of Medical Certificates of Cause of Death (MCCD) signed between 01-01-2013 and 31-12-2013 in the medical, pediatric, surgical and obstetrics/gynecology departments of Cape Coast Teaching Hospital were done, analyzing for errors using the WHO/ICD-10 guidelines as the standard. The errors were grouped into minor and major errors.Results: In all, 337 medical certificates of cause of death were audited. Majority, 212(62.9%) were issued in the internal medicine and therapeutics department. 30.86% (104) MCCDs were completed by specialists while 69.14% (233) were completed by non-specialist medical officers. Over half (56.68%) of the MCCDs had major errors while all (100%) had at least one minor error.Conclusion: Our study showed significant errors in MCCD records, with the errors more likely in certificates issued by non-specialist medical officers. All the certificates audited had at least one minor error. Training of doctors on proper completion of MCCDs is strongly advocated.Funding: None of the authors received any financial support for this study.Keywords: Errors, Medical Certificate of Cause of Death, Ghan

Direct measurement of room-temperature nondiffusive thermal transport over micron distances in a silicon membrane

The >textbook> phonon mean free path of heat carrying phonons in silicon at room temperature is ~40 nm. However, a large contribution to the thermal conductivity comes from low-frequency phonons with much longer mean free paths. We present a simple experiment demonstrating that room-temperature thermal transport in Si significantly deviates from the diffusion model already at micron distances. Absorption of crossed laser pulses in a freestanding silicon membrane sets up a sinusoidal temperature profile that is monitored via diffraction of a probe laser beam. By changing the period of the thermal grating we vary the heat transport distance within the range ~1-10 ¿m. At small distances, we observe a reduction in the effective thermal conductivity indicating a transition from the diffusive to the ballistic transport regime for the low-frequency part of the phonon spectrum. © 2013 American Physical Society.This work was supported as part of the S3TEC Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Basic Energy Sciences under Award No. DE-SC0001299/DE-FG02-09ER46577 (experimental setup and data analysis). This work was also partially supported by projects NANOPOWER, Contract No. 256959; TAILPHOX, Contract No. 233883; NANOFUNCTION, Contract No. 257375; ACPHIN, Contract No. FIS2009-150; and AGAUR, 2009-SGR-150.Peer Reviewe

Direct Measurement of Room-Temperature Nondiffusive Thermal Transport Over Micron Distances in a Silicon Membrane

The “textbook” phonon mean free path of heat carrying phonons in silicon at room temperature is ∼40  nm. However, a large contribution to the thermal conductivity comes from low-frequency phonons with much longer mean free paths. We present a simple experiment demonstrating that room-temperature thermal transport in Si significantly deviates from the diffusion model already at micron distances. Absorption of crossed laser pulses in a freestanding silicon membrane sets up a sinusoidal temperature profile that is monitored via diffraction of a probe laser beam. By changing the period of the thermal grating we vary the heat transport distance within the range ∼1–10  μm. At small distances, we observe a reduction in the effective thermal conductivity indicating a transition from the diffusive to the ballistic transport regime for the low-frequency part of the phonon spectrum

Reconstructing phonon mean free path contributions to thermal conductivity using nanoscale membranes

Knowledge of the mean free path distribution of heat-carrying phonons is key to understanding phonon-mediated thermal transport. We demonstrate that thermal conductivity measurements of thin membranes spanning a wide thickness range can be used to characterize how bulk thermal conductivity is distributed over phonon mean free paths. A non-contact transient thermal grating technique was used to measure the thermal conductivity of suspended Si membranes ranging from 15 to 1500 nm in thickness. A decrease in the thermal conductivity from 74% to 13% of the bulk value is observed over this thickness range, which is attributed to diffuse phonon boundary scattering. Due to the well-defined relation between the membrane thickness and phonon mean free path suppression, combined with the range and accuracy of the measurements, we can reconstruct the bulk thermal conductivity accumulation vs. phonon mean free path, and compare with theoretical models

Maternity care provider knowledge, attitudes, and practices regarding provision of postpartum intrauterine contraceptive devices at a tertiary center in Ghana

ObjectiveTo assess knowledge, attitudes, and practices of maternity care providers regarding the provision of postpartum intrauterine contraceptive devices (IUDs) in Komfo Anokye Teaching Hospital (KATH), Kumasi, Ghana.MethodsA descriptive, cross‐sectional study was conducted between June 28 and July 15, 2011. Specialists, residents, house officers, and nurse midwives who had been working in the Department of Obstetrics and Gynecology for at least 3 months were included. Self‐administered questionnaires assessed formal training, current proficiency in IUD insertion, and attitudes toward postpartum IUD provision.ResultsOf 91 providers surveyed, 70 (77%) reported previous training in contraceptive counseling. Fewer than one in three respondents had ever inserted an IUD: 17 (44%) of 39 physicians and 9 (17%) of 52 midwives reported ever having inserted an IUD. A total of 33 (36%) respondents reported that they would recommend an IUD in the immediate postpartum period.ConclusionAlthough most maternity care providers at KATH had received training in contraceptive counseling, few felt confident in their ability to insert an IUD. Further training in postpartum contraceptive management is needed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135552/1/ijgo137.pd