Electric current control of spin helicity in an itinerant helimagnet

Chirality is breaking of mirror symmetry in matter. In the fields of biology and chemistry, this is particularly important because some of the essential molecules in life such as amino acids and DNA have chirality. It is a long-standing mystery how one of the enantiomers was chosen at the beginning stage of life. The understanding of the emergence of homochirality under some conditions is indispensable for the study of the origin of life as well as pharmaceutical science. The chirality is also emergent in magnetic structures. The longitudinal helical magnetic structure is the chiral object composed of magnetic moments, in which the ordered direction of the magnetic moment spatially rotates in the plane perpendicular to the propagation vector (Fig. 1a). Since the sense of rotation, which is denoted as helicity, is reversed by any mirror operation, it is corresponding to the chirality. Here we show that the chirality of a longitudinal helical structure can be controlled by the magnetic field and electric current owing to the spin-transfer torque irrelevant to the spin-orbit interaction and probed by electrical magnetochiral effect, which is sensitive to the chiral symmetry breaking, in an itinerant helimagnet MnP. This phenomenon is distinct from the multiferroicity in transverse-type insulating helical magnets, in which the helical plane is parallel to the propagation vector, because the magnetic structure has polar symmetry not chiral one. While the combination of the magnetic field and electric current satisfies the symmetrical rule of external stimulus for the chirality control, the control with them was not reported for any chiral object previously. The present result may pave a new route to the control of chiralities originating from magnetic and atomical arrangements.Comment: 14 pages, 7 figure

Integrated Pest Management and Protection Practices by Limited Resource Farmers

This article focuses on the perceptions of limited resource farmers (LRFs) on integrated pest management (IPM) and protection practices. Data were collected from 90 LRFs in the Alabama Black Belt and analyzed by descriptive statistics. The results revealed that most farmers used pesticides and practiced crop rotation and other practices, yet a majority was not familiar or inadequately familiar with IPM. It is recommended that instituting a coordinated or seamless IPM education program on a long-term or continuing basis will enable the LRFs to be well familiar with and also practice IPM on a sustained basis

The Impact of Selected Socioeconomic Factors on Asset Building in Rural Communities

The study examined the impact of selected socioeconomic factors on asset building. Using a questionnaire, data were obtained from a convenience sample of 204 participants from several Alabama Black Belt Counties, and analyzed using descriptive statistics and logit analysis. The results showed that a majority (64%) was willing to participate in an asset building program. Of this, an overwhelming majority (at most 70%) wanted to set up a small business; further their education, or purchase a home. In addition, one socioeconomic factor, age, had a statistically significant (p = 0.016) effect on willingness to participate in an asset building program. Consequently, it was recommended that policies and programs that encourage participation in asset building be put in place for residents in the study area, focusing on age as a key factor, among others, to improve wealth. Critical resources to use in this effort are the community-based organizations, and research institutions

A large area cosmic muon detector located at Ohya stone mine

The chemical composition of the primary cosmic rays between 10 to the 15th power eV and 10 to the 18th power eV were determined by a Large Area Cosmic Muon Detector located at Ohya stone mine. The experimental aims of Ohya project are; (1) search for the ultra high-energy gamma-rays; (2) search for the GUT monopole created by Big Bang; and (3) search for the muon bundle. A large number of muon chambers were installed at the shallow underground near Nikko (approx. 100 Km north of Tokyo, situated at Ohya-town, Utsunomiya-city). At the surface of the mine, very fast 100 channel scintillation counters were equipped in order to measure the direction of air showers. These air shower arrays were operated at the same time, together with the underground muon chamber

Prevalence and Associated Risk Factors of Symptomatic Dry Eye in Ghana: A cross-sectional population-based study

Purpose This study sought to estimate the prevalence and associated risk factors of symptomatic dry eye in the general non-clinical Ghanaian population. Methods This was a cross-sectional population-based study conducted from November 2019 to February 2020. A stratified, multistage, random sampling technique was used to select participants aged 18 years and above from the capital cities of eight administrative regions in Ghana. Symptomatic dry eye was assessed using the Ocular Surface Disease Index questionnaire (OSDI). A study specific structured questionnaire was administered to collect information on participants’ demographics and self-reported risk factors of dry eye disease such as smoking, diabetes, hypertension, arthritis, ocular allergies, pregnancy, contact lens wear, use of topical glaucoma medication and multivitamin supplement. Multiple linear regression analysis was used to explore associations between symptomatic dry eye and participant characteristics. A p-value of 0.05 was considered statistically significant

High-Temperature Stable Operation of Nanoribbon Field-Effect Transistors

We experimentally demonstrated that nanoribbon field-effect transistors can be used for stable high-temperature applications. The on-current level of the nanoribbon FETs decreases at elevated temperatures due to the degradation of the electron mobility. We propose two methods of compensating for the variation of the current level with the temperature in the range of 25–150°C, involving the application of a suitable (1) positive or (2) negative substrate bias. These two methods were compared by two-dimensional numerical simulations. Although both approaches show constant on-state current saturation characteristics over the proposed temperature range, the latter shows an improvement in the off-state control of up to five orders of magnitude (−5.2 × 10−6)