Dan Grinstein’s research while affiliated with Ariel University and other places

We show that 1‐(2‐hydroxyethyl)‐1H‐imidazol‐3‐ium and 1‐(2‐hydroxyethyl)‐3‐methyl‐1H‐imidazol‐3‐ium salts, as well as the salts of their nitrite esters, that include oxidizing anions (so‐called explosphores) such as nitrate, picrate and perchlorate„ are endowed with high enthalpies of decomposition, high decomposition temperatures, and high densities. This combined with detonation velocities and pressures calculated using Explo5, indicates that especially the perchlorate salts have potential as energetic materials. All the studied salts are easily preparable in up to gram scale through two or three synthetic steps from simple imidazole. Many of these salts are ionic liquids, which may render them useful as energetic plasticizers or gel filled materials.

Background Post-Traumatic Stress Disorder (PTSD) symptoms include re-experiencing, avoidance, hyperarousal, and cognitive deficits, reflecting both emotional and cognitive dysregulation. In recent years, non-pharmacological approaches and specifically animal-assisted therapy have been shown to be beneficial for a variety of disorders such as Attention-Deficit/Hyperactivity Disorder, Autism Spectrum Disorder, and PTSD. However, little is mentioned in the literature about the reciprocal effects of the animal–human interaction. Objective To evaluate the effects of a one-year dog training programme on PTSD symptomatology in youngsters with PTSD and on dogs’ behaviour. Methods Fifty-three adolescents, previously exposed to interpersonal trauma, were clinically diagnosed with PTSD and assigned to a dog-training programme group (n = 30) and a control group (n = 23) that engaged in other training programmes (e.g. cooking, hairstyling, etc.). Both groups were evaluated at baseline and following 12-months by The Clinician-Administered PTSD Scale for DSM-5 in Children and Adolescents (CAPS-CA-5) and Beck-Depression Inventory (BDI). Additionally, we physiologically measured both emotional and attention dysregulation. Results Post-12-months training, a significant alleviation of PTSD symptomatology accompanied by lower depression severity was observed in the dog-training group, compared with a insignificant recovery in the control group. Furthermore, improved emotional and attentional regulation was observed in the dog-training group. Measuring the dogs’ behaviour revealed increased anxiety and decreased selective attention performance, which was inversely correlated with the beneficial effects observed in the dog-training programme group. Conclusions Our findings emphasize the role of emotional and attentional regulations on the dog–handler interface, as evidence-based support for the beneficial effects of the dog-training programme, as either a non-pharmacological intervention or as complementary to anti-depressants treatment of PTSD. Though pharmacological treatments increase the patients’ well-being by treating certain PTSD symptoms, our suggested dog-training programme seems to influence the PTSD diagnostic status, thus may be implemented in civilians and veterans with PTSD.

The ability to extract reliable segments from the sensory data-stream is necessary for learning and for creating a reliable representation of the environment. Here we focused on segmentation in visual learning associated with foraging. Fifty-one pigeons (Columba livia) were trained to recognize two food-predicting signals, one presented against fixed background elements and the other against varying backgrounds. The pigeons were divided into two groups: 32 pigeons were trained with short intervals of 3-5 minutes between sessions and 19 with long intervals of 60 minutes between sessions. When tested on the signal with a plain background, 24 pigeons trained with the short time intervals preferred the signal presented against a varying background during training and eight preferred the signal presented against a fixed background during training. Nine pigeons trained with the long intervals preferred the signal presented against a varying background during training and ten the signal presented against a fixed background during training. Our findings indicate that pigeons possess an ability to use variation-set structure to segment visual data. To date, the effect of variation-set structure has been demonstrated only in the context of human language acquisition. Our current findings suggest that variation sets structure may be linked to other learning abilities too.

There is a consensus that humans, rodents, and primates process odor mixtures configurally: that is, the mixture is perceived as a unique whole and not as a collection of its different components. However, it is commonly believed by dog trainers that dogs can analyze mixtures and break them down into their individual components: that is, that they process odor mixtures analytically. There is, however, little experimental evidence to support this belief. This experiment was designed to determine whether dogs trained on mixtures of three or five different odors would detect the individual odors when each component was tested. Our results show that the dogs were able to respond to each of the components on their first trial with each separate element of the mixture (p < 0.001). This finding presents the first experimental proof that dogs trained to detect a mixture will later detect its individual components. These results may be attributed to previous extensive general training of the tested dogs to detect odors, and to their being reared and maintained in an enriched olfactory environment.

Hydrogen sensing in real environments is an important issue on the pathway toward the hydrogen economy. The use of semiconductor-based sensing layers has significantly advanced the detection limit of the H2 sensor, in part thanks to the additional use of catalytic metals which effectively dope their electron depletion layer. Nevertheless, these high-end sensors are highly sensitive to the environmental parameters (temperature and humidity) and require a complex fabrication process. Herein, we report a colloidal approach to the fabrication of indium-tin oxide combined with palladium-nickel or platinum nanoparticles sensing layer. The cross-sections of the sensing layers show the network of nanoparticles and voids responsible for the excellent sensing properties they display. The sensors show sensitivity from 4 % down to 70 ppm of H2 and repeatability in that range. Moreover, the sensors have a unique ability to be tolerant to the humidity level with similar sensing response whatever the humidity level in the broad range from 0 to 60 % relative humidity. This tolerance is attributed to the organic layer coating the nanoparticles.

Aggression in psychiatric wards is a continuing matter of concern for both patients and medical staff. Here we have tested the hypothesis that the frequency of such incidents can be reduced with a new strategy of using trained alert dogs that warn of impending violent outbursts. Dogs were positioned among patients in psychiatric wards. Analyses show that the dogs warned of impending aggressive outbursts, responding to signals from a specific patient out of a group of unfamiliar psychotic patients. Their alerts were not a response to stress as canine cortisol levels were not significantly changed. Visual glance was the preferred method used by young dogs to respond to patient. Until a similar electronic technology is developed, trained alert dogs can help caregivers to protect both the patient and those around them from injuries that may otherwise result from aggressive outbursts in psychiatric patients.

There is much current interest in materials that are made entirely or mostly of nitrogen atoms. Such materials, polynitrogens, may reveal new aspects of nitrogen chemistry, and are believed to provide a possible basis for novel energetic substances. An interesting family of such materials, in which the N5⁺group appears as a cation, was prepared by K. O. Christe and coworkers. Little is known as yet on the microscopic properties of these materials. In this paper, we report theoretical calculations to predict the structure, energetic stability and decomposition dynamics of the polynitrogen molecule N5⁺B(N3)4⁻, the building block of a solid prepared by K. O. Christe, and of the dimer of this molecule. The structures are computed at the B3LYP-D3 level of DFT. Ab Initio Molecular Dynamics simulations are used to explore the thermal stability of the species and the decomposition mechanism. It is found that the N5⁺B(N3)4⁻ molecule decomposes on a picosecond timescale at T=200K, with an ultrafast release of four N2 molecules, which is very exothermic. The species BN9 is a product. The dimer is considerably more stable. Sensitivity of the process to temperature and to an applied force is reported. Possible applications of this material are briefly discussed.

Novel, simple‐to‐make energetic mono‐ and bisvinylimidazolium perchlorate monomers are prepared and characterized. These energetic monomers offer the possibility to 3D print energetic polymers that may allow decreasing the content of the energetic filler in energetic devices without compromising their energetic properties. The new printable materials are suited for photocuring‐based additive manufacturing (AM), techniques, offering not only a large degree of control over the mechanical and energetic properties of the resulting solids, but also the production of complex geometries at high resolution.

This study addresses the use of a shrinking core model in order to evaluate the combustion behavior of boron pyrotechnic clusters suspended in a kerosene-based gel fuel. Boron particles are combined in a low-oxidizer pyrotechnic mixture forming clusters that are dispersed in the gel droplet. During the combustion of the gel droplet, the organic phase evaporates from the droplet surface, forming a porous layer of dry particles. The pyrotechnic clusters are designed to ignite after the formation of the dry layer, when boron particles are not bonded by any liquid phase and can be easily dispersed. It is established that the time needed to reach initial boron scattering depends on the droplet diameter and absorbed heat flux. No dependence of the time delay for initial boron scattering on the boiling temperature is observed. Three pyrotechnic mixtures are used in order to investigate the influence of the pyrotechnic activation temperature on the formation of the dry layer. Boron pyrotechnic dispersion based on ammonium perchlorate (NH4ClO4) is limited to a low gel boiling temperature; whereas pyrotechnic dispersion based on NaClO4 or potassium perchlorate, which each have a higher activation temperature, can ensure the formation of a dry layer that allows scattering of the boron particles.