Intermolecular Forces Driving Hexamethylenetetramine Co-Crystal Formation, a DFT and XRD Analysis

Interest in co-crystals formation has been constantly growing since their discovery, almost a century ago. Such success is due to the ability to tune the physical-chemical properties of the components in solid state by avoiding a change in their molecular structure. The properties influenced by the co-crystals formation range from an improvement of mechanical features and chemical stability to different solubility. In the scientific research area, the pharmacological field is undoubtedly one of those in which an expansion of the co-crystal knowledge can offer wide benefits. In this work, we described the crystalline structure of hexamethylenetetramine co-crystallized with the isophthalic acid, and we compared it with another co-crystal, showing the same components but different stoichiometry. To give a wider overview on the nature of the interactions behind the observed crystal packing and to rationalize the reasons of its formation, a computational analysis on such structures was carried out.

Geothermal Assessment of Target Formations Using Recorded Temperature Measurements for the Alberta No. 1 Geothermal Project

The Alberta No. 1 project is a planned power and heat (direct use) geothermal project located within the County of Grande Prairie and Municipal District of Greenview. For the project to successfully produce power and heat on a commercial scale, temperatures of 120 °C are desirable. The produced fluids must also be from highly permeable formations from depths of less than 4500 m. Bottomhole temperature measurements and wireline logs from Alberta’s extensive oil and gas database were used to determine the depths to target formations and temperatures within these formations in the project area. The target formations include the dolomitized carbonate units of Devonian age from the Beaverhill Lake Group to the top of the Precambrian Basement. Permeable Devonian-aged sandstone units such as the Granite Wash Formation are also targets. Results suggest that elevation to the top of the Beaverhill Lake Group range from 3104 m to 4094 m and temperatures at the top of the formation range from 87 °C to 123 °C in the study area. Elevation to the top of the Precambrian Basement ranges from 3205 m to 4223 m and temperatures at the formation top range from 74 °C to 124 °C. Within the area where Alberta No. 1 plans to drill, temperatures close to and exceeding 120 °C are expected within the target formations.

Geotechnical Evaluation of Limestones from Cape Monze and Adjoining Areas, Karachi, Pakistan for Their Utilization as Road Aggregate

Limestone samples (n = 19) were collected from outcrops of Nari and Gaj formations for the determinationof physicochemical and mechanical characteristics. Compressive strength of Nari and Gaj formations varied in therange of 29-63 and 94-32 MPA with mean of 44 and 58 MPA respectively. Density of Gaj Formation (range: 2364-3264; mean: 2893 Kg/m3) is relatively higher than Nari Formation (range: 2321-3284; mean: 2565 Kg/m3). Meanspecific gravity of both Nari and Gaj formations is 2.5. Absorption of Nari Formation (mean: 2.64) is higher than theGaj Formation (mean: 1.78). Mean Sulphate soundness of Nari Formation (8.7%) is slightly higher than Gaj Formation(8.5%). Abrasion values of both formations are within the AASHTO reference range (< 40%) where mean value ofLoss Angles for Nari Formation is 34% and Gaj Formation is 26%. Crushing values of both Nari (10-50%) and Gaj(10-25%) formations where mean of Nari (27%) is double the mean of Gaj (13%) Formation. Mean water-solublesulphate and chloride of both formations is same (0.1% and 0.04% respectively). Both formations have alkaline pH(8.1±). Mean TOC content of Nari and Gaj formations is 0.4%. Carbonate% of Nari and Gaj formations is < 46%. Claylumps and friable particles in both formations are highly variable but the mean values are within permissible range (<1%). Elongation Index of both formations is double (30) the standard EI value (15%) set by National HighwayAuthority, Pakistan. Mean Flakiness value of both formations is 20%.

Geotechnical Evaluation of Limestones from Cape Monze and Adjoining Areas, Karachi, Pakistan for Their Utilization as Road Aggregate

Limestone samples (n = 19) were collected from outcrops of Nari and Gaj formations for the determinationof physicochemical and mechanical characteristics. Compressive strength of Nari and Gaj formations varied in therange of 29-63 and 94-32 MPA with mean of 44 and 58 MPA respectively. Density of Gaj Formation (range: 2364-3264; mean: 2893 Kg/m3) is relatively higher than Nari Formation (range: 2321-3284; mean: 2565 Kg/m3). Meanspecific gravity of both Nari and Gaj formations is 2.5. Absorption of Nari Formation (mean: 2.64) is higher than theGaj Formation (mean: 1.78). Mean Sulphate soundness of Nari Formation (8.7%) is slightly higher than Gaj Formation(8.5%). Abrasion values of both formations are within the AASHTO reference range (< 40%) where mean value ofLoss Angles for Nari Formation is 34% and Gaj Formation is 26%. Crushing values of both Nari (10-50%) and Gaj(10-25%) formations where mean of Nari (27%) is double the mean of Gaj (13%) Formation. Mean water-solublesulphate and chloride of both formations is same (0.1% and 0.04% respectively). Both formations have alkaline pH(8.1±). Mean TOC content of Nari and Gaj formations is 0.4%. Carbonate% of Nari and Gaj formations is < 46%. Claylumps and friable particles in both formations are highly variable but the mean values are within permissible range (<1%). Elongation Index of both formations is double (30) the standard EI value (15%) set by National HighwayAuthority, Pakistan. Mean Flakiness value of both formations is 20%.

Jurassic–Cretaceous radiolarian-bearing strata from the Gresten Klippen Zone and the St. Veit Klippen Zone (Wienerwald, Eastern Alps, Austria): Implications for stratigraphy and paleogeography

Two sections of the klippen zones in the Wienerwald area have been investigated for their stratigraphy: (1) The Gern section of the Main Klippen Zone, a part of the Gresten Klippen Zone, and (2) the St. Veit Klippen Zone in the Lainz Tunnel and the neighboring outcrops in western Vienna. New biostratigraphic data are based on radiolaria from siliceous intervals and a few findings of calcareous nannofossils from marlstones. In the Gresten Klippen Zone, radiolarian assemblages from limestones of the Gern locality indicate a middle Oxfordian to early Kimmeridgian age of the Scheibbsbach Formation.Radiolarian and nannofossil data from the St. Veit Klippen Zone in the Lainz railway tunnel locality, as well as correlated outcrops from the Lainzer Tiergarten and the Gemeindeberg in the southwest of Vienna, indicate the presence of mainly Bajocian to lower Oxfordian red radiolarites and cherts (Rotenberg Formation). Siliceous, grey limestones and cherts of the Fasselgraben Formation range from the upper Oxfordian–Kimmeridgian to the Valanginian–Barremian.The Main Klippen Zone was derived from the European margin to the north, and this zone is regarded as a Helvetic paleogeographic unit. The St. Veit Klippen Zone in the Lainz Tunnel section contains no ophiolitic material and shows a tectonic contact with the surrounding Rhenodanubian nappe system, which indicates no primary sedimentary contact of the St. Veit Klippen Zone with the Flysch units, as well as demonstrating the presence of two structurally separated Alpine tectonic units. Thus, a direct correlation with the Ybbsitz Zone is not supported, and an original paleogeographic position in the transition from the Penninic Ocean to the Austroalpine continental fragment is proposed.

Assessing ambient and internal environmental conditions of pit latrines in urban slums of Kampala, Uganda: effect on performance

There is increasing interest to improve the functionality and performance of pit latrines in low income urban areas. This study aimed at assessing the ambient and pit environmental conditions and their implications on the performance (smell and fly nuisance) of pit latrines. Forty-two pit latrines were investigated in urban slums of Kampala, Uganda, through field observation and measurements of ambient and pit environmental conditions. The implications were assessed using oxygen-reduction potential (ORP) and its association with smell/insect nuisances. The pit temperature (21 to 30.7 °C), pH (5.0–11.8) and ORP (−247 to 65.9 mV) were consistently, significantly different (p &lt; 0.001) between the surface and 0.5 m depth of pit content. The conditions in most (95%) pit latrines were anoxic (ORP &lt; +50 mV), and mainly within the acid formation range (ORP −199 to −51 mV). Most smelling pit latrines and flies were within the acid formation ORP range, with a significant association (gamma, G = 0.797, p = 0.014) between ORP and smell in clean latrines only. The results suggest that ventilation of pit latrines within urban slums was not sufficient. Additionally, cleanliness, moisture reduction and waste stabilisation could address bad smells in pit latrines, ultimately improving their usage in urban slums.