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Juvenile awareness programs like Scared Straight became popular crime prevention strategies during the 1970s. Juvenile offenders and at-risk youth who participate in these programs are taken to prisons where inmates use confrontational methods to recount stories about violence, sex, and abuse perpetrated by fellow inmates while living a life behind bars. These "get tough" policies have wide public and political appeal. Empirically speaking it is unclear whether juvenile awareness programs help to reduce recidivism or prevent criminal behavior. The purpose of this article is to use an evidence-based approach to determine if there is sufficient empirical evidence to suggest that these programs are effective crime prevention tools. This investigation includes a comprehensive review of the studies that have examined juvenile awareness programs. The studies are evaluated using the most widely accepted tool for assessing scholarly works in criminology, the Maryland Scientific Methods Scale. The results of this study indicate that juvenile awareness programs that use confrontational techniques do not work. However, their nonconfrontational counterparts may show some promise. (Contains 1 table.)

The Under-Frequency Load Shedding (UFLS) scheme is an emergency measure in place to prevent system collapse in the event of a large generation deficit relative to demand at any moment in time. However, the effectiveness of traditional UFLS schemes may be compromised as network power flows change due to the growth of distributed generation (DG) and a reduction in system inertia. This study has shown some of the issues affecting the UFLS protection system with rising installed capacities of DG in the Great Britain power system. Simulation results show how the effectiveness of the scheme is challenged with current and future expected DG installed capacities and the risk of over shedding demand due to the scheme’s current settings is evaluated. Many proposed improvements to traditional load shedding schemes are based on upgrades to network monitoring and communication systems, which are not yet fully available. This study evaluates more readily available solutions, including relocation of under-frequency relays and reducing the time delay of the scheme, which may provide interim improvements to the UFLS scheme, based on a case study in GB. [ABSTRACT FROM AUTHOR]

Great Britain has reached high penetrations of distributed generation (DG). Historically, there has been a lack of technical requirements for DG to provide system support and for network operators to monitor, control and gather detailed information on DG installations. As a result, much of it is unobservable and uncontrollable. This work has analysed the available data sources for the amount, size and type of DG installations in GB. It is found that the lack of transparency and consistency of data are likely to act as an obstacle to the development of a more active distribution network. The impact that high DG has on system operation and system stability is discussed, including the potential for DG to offer flexibility services. A system disturbance in GB on August 9th 2019 brought a number of issues into focus: Slow action to change inappropriate settings of DG loss‐of‐mains protection and the uncertainty that DG adds to the effectiveness of under frequency load shedding schemes. Finally, it is argued that coordination between transmission and distribution networks is central to addressing many of the challenges and is a key enabler to utilising the flexibility available from DERs and releasing capacity for more DERs to be connected. [ABSTRACT FROM AUTHOR]

Pyroxene phenocrysts from nephelinites associated with the Tertiary carbonatite-nephelinite Napak volcano are not in isotopic equilibrium with their host rocks and reveal a complicated evolutionary history that involved fractional crystallization of a melt undergoing continuous isotopic change. Intrasample pyroxene populations have different isotopic compositions and are interpreted as earlier formed pyroxenes that failed to isotopically equilibrate with the host liquids and that were later scavenged by ascending melts. The Napak data show that the pyroxenes can be effective in monitoring isotopic shifts that occur during magma evolution.

Nd and Sr isotope compositions of nephelinites, carbonatites, and phonolites from Shombole, a Pliocene volcano in East Africa, show that the phonolites cannot be derived by simple fractional crystallization of nephelinite magma. For a given initial [87.sup.SR]/[86.sup.Sr] ratio, [143.sup.Nd]/[144.sup.Nd] is lower in most phonolites than in the nephelinites and carbonatites. Interaction between nephelinitic magma and lower-crustal granulites can account for these differences. The similar ranges in isotopic composition of the carbonatites and nephelinites are consistent with repeated melting events involving heterogeneous mantle. The carbonatites could have formed by immiscibility with nephelinite magma or by direct partial melting of the same mantle source(s) as the nephelinites.

Five U-Pb zircon and four Rb-Sr whole-rock isochron dates constrain the ages of plutonic rocks and their subsequent history within the Western Ethiopian Shield. The U-Pb data show plutonic activity between 830 and 540 Ma, similar to the time span established for the Pan-African rocks of the Southern Red Sea Hills of the Sudan and the Jeddah terrane of Saudi Arabia. U-Pb zircon ages of 828 +9/-2 and 814 [+ or -] 2 Ma, obtained from pre-kinematic plutons of the Birbir Domain, date the time of their emplacement. One of these plutons (Goma) yielded a whole-rock Rb-Sr isochron date of 759 [+ or -] 18 Ma. Granite sheets within the high-grade Baro Domain, believed to be anatectic, were dated by U-Pb at 783 +19/-14 Ma. The 780-760 Ma event is interpreted as a period of Pan-African regional metamorphism that correlates with the age of low-grade metamorphism of arc-related rocks elsewhere in northeast Africa. Other reset Rb-Sr whole-rock isochrons from the Western Ethiopian Shield that cluster around 635 Ma provide evidence of significant isotopic homogenization, probably associated with major transcurrent movement parallel to a plate margin. A U-Pb lower-intercept age of 582 +29/-33 Ma from Baro granite sheets denotes a second high-grade metamorphic event and correlates with the age of Mozambiquean amphibolite-facies metamorphism in northwest Kenya. Late- to post-kinematic plutons at 571 +11/-3 and 541 +10/-16 Ma place a minimum age limit on deformation and metamorphism.

Optimisation and Analysis Toolbox for power Systems analysis (OATS) is an open-source simulation tool for steady-state analyses of power systems problems distributed under the GNU General Public License (GPLv3). It contains implementations of classical steady-state problems, e.g. load flow, optimal power flow (OPF) and unit commitment, as well as enhancements to these classical models relative to the features available in widely used open-source tools. Enhancements implemented in the current release of OATS include: a model of voltage regulating on-load tap-changing transformers; load shedding in OPF; allowing a user to build a contingency list in the security constrained OPF analysis; implementation of a distributed slack bus; and the ability to model zonal transfer limits in unit commitment. The mathematical optimisation models are written in an open-source algebraic modelling language, which offers high-level symbolic syntax for describing optimisation problems. The flexibility offered by OATS makes it an ideal tool for teaching and academic research. This paper presents novel aspects of OATS and discusses, through demonstrative examples, how OATS can be extended to new problem classes in the area of steady-state power systems analysis. [ABSTRACT FROM AUTHOR]

There is a reduction in the percentage penetration of synchronous machines within the Great Britain (GB) power system leading to a decrease in inertia and an increase in the system rate of change of frequency (RoCoF) resulting from power imbalances. This raises the challenge of containing frequency deviations to within the relevant operational limits. As a result, steps need to be taken by the system operator to manage the risk to system security. In order to better understand this risk, this article presents the challenge in light of the changing energy landscape and the current and future frequency response services available to contain frequency deviations. Although the current GB frequency response services may be capable of containing most events within frequency limits, in low-inertia scenarios, these responses alone are not capable of containing excursions within practical RoCoF limits. Consequently, further action must be taken to ensure system security. The system operator currently employs an interim solution of limiting the largest loss risk, depending on system inertia and the RoCoF limit. While this is suitable in the short term, it is unlikely that this option will be cost-effective in the future. [ABSTRACT FROM AUTHOR]

About half of the 330 occurrences listed in the global inventory of carbonatites have been dated, mostly by the K-Ar method, and they fall into groups that appear to be temporally and spatially linked to major orogenic events. Overall, however, the temporal pattern is one of exponential increase in frequency with time. This secular trend has been interpreted as an increase in carbonatite activity in the course of terrestrial evolution. In an alternative interpretation, the observed trend may be viewed as an artifact of preservation, because the probability of preservation decreases exponentially with increasing age of the crustal segments. The secular trend for carbonatites since at least 1.8 Ga, the time that continental crust attained its near-modern extent, is compatible with a steady-state process of carbonatite generation and destruction that has a half-life of approximately 445 m.y. The most acceptable model for the temporal distribution of carbonatites involves a combination of orogenic activity and erosional dispersal.

The increasing penetration of renewable generation has led to the decrease of power systems' overall inertia, which introduces significant challenges to frequency stability. In this paper, the potential of using Fast Frequency Response (FFR) to enhance frequency control in power systems with low inertia is investigated in detail. A Generic System Frequency Response (GSFR) model taking into account of the penetration level of Non-Synchronous Generation (NSG) and FFR has been developed and used to investigate the impact of reduced inertia on frequency control and demonstrate that the amount of reserve power to be scheduled can be significantly reduced with the deployment of FFR. The impact of the different FFR resources' characteristics (e.g. response delay, ramp rate, etc.) on the effectiveness of frequency control is also investigated, based on which the desirable specifications for FFR schemes are summarised. These desirable properties of FFR schemes are taken into account in the design of a wide-area monitoring and control system termed 'Enhanced Frequency Control Capability (EFCC)', which is proposed for the delivery of FFR in the future Great Britain transmission system. The design and operation of the EFCC scheme are presented, along with a case study demonstrating its effectiveness in enhancing the frequency control. [ABSTRACT FROM AUTHOR]

This paper describes the derivation of linear sensitivities used in the dispatch of MW controls for alleviation of voltage violations. Such a set of sensitivities is important for the selection and co-ordination of necessary changes to MW generation, phase shifter settings and, as a last resort, load shedding where reactive power controls are insufficient. The sensitivity analysis has been embedded in a qualitative reasoning based decision support tool in which operators' considerations such as cost, control effectiveness, preservation of control margin and ease of implementation are modeled in such a way that priorities can be adjusted and results achieved quickly. Results are presented demonstrating the accuracy and effectiveness of the proposed approach both for a standard test system and a system representing a real network. Index Terms--Fuzzy reasoning, knowledge-based systems, power system operation, power system security, sensitivity analysis, voltage control.